Biomedical subjects

Wei-Jen Chen

Publications and source records attributed to Wei-Jen Chen.

At least 37 records · Page 2Linked to original sources

PubMed2003

Induction of G1 phase arrest in MCF human breast cancer cells by pentagalloylglucose through the down-regulation of CDK4 and CDK2 activities and up-regulation of the CDK inhibitors p27(Kip) and p21(Cip).

Pentagalloylglucose (5GG) is a potent and specific inhibitor of NADPH dehydrogenase or xanthine oxidase. In our previous study, we showed that 5GG was able to induce apoptosis in HL-60 cells in a time- and concentration-dependent manner via the activation of caspase-3. Recently, we found that 5GG was capable of perturbing the cell cycle of the human breast cancer cell line MCF-7. DNA flow cytometric analysis showed that 5GG exhibited the ability of blocking MCF-7 cell cycle progression at the G1 phase. The level of several G1 phase-related cyclins and cyclin-dependent kinases did not change in these cells during a 24-hr exposure to 5GG. However, the activity of cyclin E/CDK2 was decreased in a concentration- and time-dependent manner and the activity of cyclin D/CDK4 was inhibited when serum-starved synchronized cells were released from synchronization. p27(Kip) and p21(Cip), inhibitors of cyclin/CDK complexes in G1-phase, were gradually increased after 5GG treatment in a time-dependent manner and the induction of p21(Cip) was correlated with an increase in p53 levels. These results suggest that the suppression of cell-cycle progression in the G1 phase by 5GG was mediated in MCF-7 cells, at least in part, by either the inhibition of cyclin D/CDK4 and cyclin E/CDK2 activity or the induction of the CDK inhibitors p27(Kip) and p21(Cip).

Breast Neoplasms↗

PubMed2003

Circulating soluble Fas in patients with breast cancer.

It has been suggested that circulating soluble Fas (sFas) contributes to tumor progression. However, little is known about the role of sFas in breast cancer. This study was designed with the aim of elucidating the possible relation between sFas and breast cancer. A series of 57 consecutive patients with invasive breast cancer undergoing surgery were prospectively included in the study and evaluated. Venous blood samples were collected before surgery. Sera were obtained by centrifugation and stored at -70 degrees C until assayed. The control group consisted of 12 patients with benign breast tumors (6 with fibrocystic disease, 6 with fibroadenoma). Serum concentrations of sFas were measured by the quantitative sandwich enzyme immunoassay technique. The data on primary tumor staging, age, estrogen receptor status, lymph node status, tumor grading, and TNM staging were reviewed and recorded. The mean value of circulating sFas in patients with invasive breast cancer was 794.2 +/- 183.0 pg/ml and that of the control group 582.1 +/- 62.8 pg/ml; the difference was significant (p < 0.001). Furthermore, there were significantly higher serum levels of sFas in the older patients (age > or = 50) (p = 0.020) and in those with a more advanced TNM stage (p = 0.021). In the multivariate analysis, TNM stage (p = 0.005) appeared to be an independent factor for significantly higher circulating sFas in patients with invasive breast cancer. Thus circulating sFas levels may reflect the severity of invasive breast cancer. Hence the possible prognostic value of sFas for breast cancer deserves further elucidation and evaluation with long-term patient follow-up.

Adult↗

PubMed2003

Castleman disease of the pleura: experience with eight surgically proven cases.

BACKGROUND: Castleman disease of the pleura is unusual, and we present our experience with eight surgically proven cases. METHODS: Between 1980 and 2002, 8 patients (7 women and 1 man; age range, 20 to 53 years; mean, 26.5 years) with surgically proven, pleural Castleman disease (six hyaline vascular type, one plasma cell type, and one mixed type) were encountered. Their clinical, imaging, and surgical findings were reviewed. RESULTS: Five patients were asymptomatic, 1 had dyspnea, 1 had cough, and 1 experienced chest discomfort. Chest radiography showed a well-circumscribed interlobar, cardiophrenic, or paraaortic mass in 6 patients, a massive effusion in 1, and a focal diaphragmatic bulge in 1. Six tumors showed varying degrees of contrast enhancement (10 to 95 HU; mean, 46 HU) on computed tomography. Three cases appeared as well-defined, heterogeneously hyperintense pleural masses on magnetic resonance imaging. The masses varied in size from 3 to 10 cm (mean, 5.2 cm). Five masses greater than 5 cm had prominent pleural arterial blood supply and severe adhesions requiring thoracotomy and resection of nearby structures for radical tumor excision. Blood loss from patients varied between 100 and 850 mL (mean, 620 mL). No tumor recurrence was noted during follow-up (range, 1 to 16 years; mean, 6.5 years). CONCLUSIONS: Pleural Castleman disease predominately affects young women and manifests as a well-circumscribed mass with a varying degree of contrast enhancement on computed tomography and heterogeneity on magnetic resonance imaging. Tumors greater than 5 cm have profuse pleural blood supplies and severe adhesion necessitating open thoracotomy and resection of neighboring structures. Radical resection can produce a satisfactory outcome.

Adult↗

PubMed2003

Repeatability of clades as a criterion of reliability: a case study for molecular phylogeny of Acanthomorpha (Teleostei) with larger number of taxa.

Although much progress has been made recently in teleostean phylogeny, relationships among the main lineages of the higher teleosts (Acanthomorpha), containing more than 60% of all fish species, remain poorly defined. This study represents the most extensive taxonomic sampling effort to date to collect new molecular characters for phylogenetic analysis of acanthomorph fishes. We compiled and analyzed three independent data sets, including: (i) mitochondrial ribosomal fragments from 12S and 16s (814bp for 97 taxa); (ii) nuclear ribosomal 28S sequences (847bp for 74 taxa); and (iii) a nuclear protein-coding gene, rhodopsin (759bp for 86 taxa). Detailed analyses were conducted on each data set separately and the principle of taxonomic congruence without consensus trees was used to assess confidence in the results as follows. Repeatability of clades from separate analyses was considered the primary criterion to establish reliability, rather than bootstrap proportions from a single combined (total evidence) data matrix. The new and reliable clades emerging from this study of the acanthomorph radiation were: Gadiformes (cods) with Zeioids (dories); Beloniformes (needlefishes) with Atheriniformes (silversides); blenioids (blennies) with Gobiesocoidei (clingfishes); Channoidei (snakeheads) with Anabantoidei (climbing gouramies); Mastacembeloidei (spiny eels) with Synbranchioidei (swamp-eels); the last two pairs of taxa grouping together, Syngnathoidei (aulostomids, macroramphosids) with Dactylopteridae (flying gurnards); Scombroidei (mackerels) plus Stromatoidei plus Chiasmodontidae; Ammodytidae (sand lances) with Cheimarrhichthyidae (torrentfish); Zoarcoidei (eelpouts) with Cottoidei; Percidae (perches) with Notothenioidei (Antarctic fishes); and a clade grouping Carangidae (jacks), Echeneidae (remoras), Sphyraenidae (barracudas), Menidae (moonfish), Polynemidae (threadfins), Centropomidae (snooks), and Pleuronectiformes (flatfishes).

Animals↗

PubMed2003

Obstructive jaundice alters LFA-1alpha expression in rat small intestine.

Translocation of bacteria and endotoxtin has long been documented in obstructive jaundice, and altered intestinal barrier function is considered to be one of the important mechanisms for this phenomenon. The regulation of gastrointestinal mucosal response to injury is thus of important clinical as well as biological relevance. Integrins play a critical role in enterocyte migration, which is essential to mucosal healing. This study is designed to evaluate the integrins status in obstructive jaundice. Male Sprague-Dawley rats (N = 37) were randomized to three groups. Group 1 (N = 12) underwent common bile duct ligation (CBDL), group 2 (N = 12) underwent common bile duct ligation with oral glutamine administration (CBDL + G), and group 3 (N = 13) underwent a sham operation (sham control). After seven days, segments of proximal jejunum and distal ileum were harvested, and cell surface immunohistochemical expression of LFA-1alpha and VLA-6 were evaluated and recorded. The staining intensities were graded on a scale of 0-4. Comparisons among the three groups were performed. There was no significant difference in VLA-6 staining on small intestine among the three groups (P > 0.05). There was also no significant difference in LFA-1alpha staining the on jejunum between group 1 (CBDL) and group 3 (sham control) (P > 0.05). However, the LFA-1alpha staining on the ileum in group 1 (CBDL) significantly decreased when compared with group 3 (sham control) (P = 0.008). With oral glutamine administration (0.2 g/kg body weight, once daily), LFA-1alpha staining on the ileum was significantly restored in group 2 (CBDL + G). In conclusion, obstructive jaundice for one week down-regulates LFA-1alpha expression on rat ileum. With oral glutamine administration, such down-regulation of LFA-1alpha expression on rat ileum can be restored. Such a phenomenon is intriguing and deserves further evaluation and elucidation.

Animals↗

PubMed2003

Retrobulbar cellular schwannoma. Two cases report and review of the literature.

Cellular schwannoma is a variant of classical schwannoma that is characterized by high cellularity. As it is accompanied by mitotic figures, it is easily mistaken for a malignant neoplasm. However, hyalinized thick-walled blood vessels, an alternating growth pattern of spindle-shaped neoplastic cells, and even Verocay bodies can be found. It is most commonly seen in the paravertebral area, particularly in the mediastinum and retroperitoneum. Retrobulbar cellular schwannoma is uncommon, and only one case has been reported to date. In this study, we report two additional cases of retrobulbar cellular schwannoma that recurred two years after surgery. We suggest that the patient be given an aggressive postoperative treatment because a successful, complete excision cannot be guaranteed at such an anatomic site.

Adult↗

PubMed2003

Transradial intracoronary catheter-aspiration embolectomy for acute coronary embolism after mitral valve replacement.

An anticoagulated 51-year-old woman with a mechanical mitral prosthesis, which had been implanted 12 years earlier, sustained an acute anterior wall myocardial infarction caused by an embolus in the mid left anterior descending coronary artery. After treatment with tissue-plasminogen activator failed to lyse the obstruction, we performed intracoronary catheter-aspiration embolectomy via a transradial approach, which yielded a favorable result.

Acute Disease↗

PubMed2002

Penta-O-galloyl-beta-D-glucose inhibits the invasion of mouse melanoma by suppressing metalloproteinase-9 through down-regulation of activator protein-1.

Penta-O-galloyl-beta-D-glucose (5GG) inhibited the invasion of highly metastatic mouse melanoma B16F10 cells in vitro, as demonstrated by transwell assay. Its ability to diminish the activity of matrix metalloproteinase (MMP) was demonstrated by zymographic assay. Our data showed 5GG could diminish the activity of MMP-9 more than that of MMP-2. The effect on MMP-9 was elicited in a dose- and time-dependent manner, with IC50 of 15 microM. Next, we analyzed the amounts of MMP-9 and MMP-2 protein in conditioned media and in the cells. The data indicated MMP-9 proteins were also suppressed by 5GG in the same manner. In accordance with these data above, the results of reverse transcriptase polymerase chain reaction (RT-PCR) and Northern blot analysis showed a reduced level of MMP-9 mRNA. Furthermore, we studied transcription factor binding to MMP-2 and MMP-9 promoter regions by electrophoretic mobility shift assay (EMSA) in the nucleus. The results suggested that the transcription factor binding activities of Activator protein-1 (AP-1) and Sp-1 sites was mainly down-regulated by 5GG in the concentration range of 5-15 microM, but not that of nuclear factor kappaB (NF-kappaB), polioma enhancer activator 3 (PEA-3), and Activator protein-2 (AP-2) sites. The Western blot analysis of AP-1 nuclear protein showed a reduced level of c-Jun but not of c-Fos. In addition, the expression of Sp-1 and c-Jun protein was also suppressed. To elucidate whether the transcriptional activity of AP-1 or Sp-1 sites is more important, we transfected MMP-9/luciferase reporter vector, under MMP-9 promoter control, into the cells. We found that a decreased transcriptional activity of AP-1 sites is sufficient to reduce MMP-9 promoter activity. These results lead us to conclude that 5GG restricts the invasive ability of B16F10 mouse melanoma cells by reducing MMP-9 activity, by suppressing the transcriptional activity of AP-1 sites and the expression of c-Jun protein. The result may provide a potential mechanism for 5GG in cancer chemopreventive action.

Animals↗

PubMed2002

Systemic immune response after laparoscopic and open cholecystectomy.

The laparoscopic approach is thought to reduce the postoperative immunologic and metabolic effects of an open operation. This study was designed with the aim of comparing the systemic immune response after laparoscopic and open cholecystectomy. Seventeen patients with gallbladder stones were assigned to undergo either a laparoscopic (n = 9) or open (n = 8) approach. The postoperative immune response was assessed by measuring the serum levels of soluble Fas (sFas), soluble L-selectin (sL-selectin), and transforming growth factor-beta1 (TGFbeta1) preoperatively and 2 hours, 1 day, and 2 days postoperatively. Both approaches resulted in a significant decrease in sFas levels 1 and 2 days postoperatively. The open approach evoked a transient increase in sL-selectin levels 2 hours postoperatively. Moreover, the open approach resulted in a persistent, significant increase in TGFbeta1 levels postoperatively. Comparison of open versus laparoscopic cholecystectomy has shown no significant difference in sFas level and a statistically significant increase of sL-selectin (within 2 hours) and TGFbeta levels after open surgery. Although both laparoscopic and open cholecystectomy evoked an alteration of the systemic immune response, our data showed that such immune response may be less after the laparoscopic approach.

Adult↗

PubMed2002

Effect of bile acid replacement on endotoxin-induced tumor necrosis factor-alpha production in obstructive jaundice.

There is a high incidence of perioperative morbidity and mortality in patients with obstructive jaundice due to sepsis. Tumor necrosis factor-a (TNF-alpha) is considered a crucial mediator in inducing and processing the inflammatory cascade. We hypothesize that obstructive jaundice leads to an increased endotoxin-induced TNF-alpha production and that intestinal bile acid replacement can prevent this phenomenon. Sprague-Dawley rats were randomized to three groups of 12 animals each. Group 1 underwent common bile duct ligation (CBDL) with oral intestinal bile acid (deoxycholic acid 5 mg/100 g body weight/3 times daily) replacement (CBDL + bile acid); group 2 underwent common bile duct ligation with the same amount of normal saline replacement orally (CBDL + saline); and group 3 underwent a sham operation (sham control). After 2 days, endotoxin was given to the animals, and after 90 minutes, tissues (liver and lung) and blood were collected for checking the TNF-alpha levels and biochemical analyses. Comparisons among these three groups were performed and recorded. While serum and tissue (liver and lung) TNF-alpha levels of group 2 (CBDL + saline) were significantly increased after endotoxin challenge, these elevations were reduced to control levels (sham control) following oral replacement of intestinal bile acid (CBDL + bile acid). Obstructive jaundice leads to an increased endotoxin-induced TNF-alpha production and intestinal bile acid replacement can inhibit this phenomenon.

Animals↗

PubMed2002

Primary mesenchymal chondrosarcoma of the lung.

Mesenchymal chondrosarcoma has been well documented in the somatic soft tissue and bone. It is a rare subtype of chondrosarcoma characterized by the presence of islands of chondroid or by less osteoid tissue enmeshed within dense sheets of primitive small blue mesenchymal cells with hemangiopericytoma-like vessels, or by both. The vast majority of previously published pulmonary mesenchymal chondrosarcoma was metastatic. To the best of our knowledge, only one case of primary pulmonary mesenchymal chondrosarcoma has been described in the literature. Herein, we report the second case of primary mesenchymal chondrosarcoma of the lung and emphasize that biopsy may yield only nonspecific small blue cells, whereas a detailed evaluation of the resected specimen allows definite diagnosis of this rare lung tumor.

Adult↗

PubMed2002

Phylogeny of Antarctic dragonfishes (Bathydraconidae, Notothenioidei, Teleostei) and related families based on their anatomy and two mitochondrial genes.

Although Antarctic teleosts of the suborder Notothenioidei are well studied, the status of some families remains unclear because of limited taxonomic sampling and sometimes poor statistical support from molecular phylogenies. It is true for the Bathydraconidae, the sister-family of the famous haemoglobin-less icefishes, the Channichthyidae. The present study is aimed at clarifying bathydraconid phylogeny and the interrelationships of higher notothenioid families, taking nototheniids as the outgroup. For this purpose, about 300 positions in the mitochondrial control region, 750 positions in the cytochrome b, and a matrix of morphological characters were employed for separate and simultaneous phylogenetic analyses. We conclude that (1) molecular data strongly support the split of bathydraconids into three clades, here called the Bathydraconinae (Bathydraco, Prionodraco, Racovitzia), the Gymnodraconinae (Gymnodraco, Psilodraco, Acanthodraco), and the Cygnodraconinae (Cygnodraco, Gerlachea, Parachaenichthys). Interrelationships between these three and the Channichthyidae remain unclear. Molecular data support neither paraphyly nor monophyly of the bathydraconids, while morphology leads to the monophyly of the family based on the synapomorphic loss of the spinous dorsal fin; (2) The Channichthyidae, the Harpagiferidae, and the Artedidraconidae are monophyletic families; (3) the phylogeny of the haemoglobin-less channichthyids is completely resolved and congruent with the conclusions of based on anatomical characters; (4) The present molecular results as well as other molecular studies favour the hypothesis that harpagiferids are the sister-group of artedidraconids, though our morphological matrix puts harpagiferids as the sister-group of all other families on the basis of a single character. With regard to harpagiferid relationships, it is interesting to notice that, when analysed simultaneously, morphological characters are not automatically "swamped" within molecular ones: in the tree based on the simultaneous analysis of all available data, morphological characters impose their topology on molecules.

Animals↗

PubMed2002

Solitary fibrous tumor of the abdominal wall: a report of two cases immunohistochemical, flow cytometric, and ultrastructural studies and literature review.

Solitary fibrous tumors have been described at many extrapleural sites in recent years. However, solitary fibrous tumors arising from somatic soft tissue occur only rarely and can pose problems in the differential diagnosis from other benign or malignant soft tissue tumors. The majority of solitary fibrous tumors occurring in the somatic soft tissue have been found in the extremities and limb girdles, and the head and neck regions. There have been only eight published cases located in the abdominal wall. We herein report two female patients who developed solitary fibrous tumors of the abdominal wall that were not in association with the underlying peritoneum. Histologically, both tumors were characterized by a variety of architectural patterns, alternating hypercellular and hypocellular areas, proliferation of plump spindle cells, thick keloid-like and/or amianthoid collagen bundles, and ectatic staghorn-like vessels. Both tumors showed a diffuse strong reaction for CD34 and vimentin as well as focal positivity for bcl-2 and smooth muscle actin. A striking predominance in females was found in a literature review of solitary fibrous tumors of the abdominal wall, contrasting with other somatic soft tissue sites which show an equal gender distribution. Interestingly, expression of estrogen but not progesterone receptor was observed in both tumors. Ultrastructurally, the tumor cells displayed features of fibroblasts with dilated branching rough endoplasmic reticulum (RER) and Golgi apparatus. Both tumors assayed by flow cytometry demonstrated a diploid DNA content with an S-phase fraction of 7.9% and 11.4%, respectively. At follow up, both patients were well without evidence of recurrence or metastasis after surgical excision.

Abdominal Neoplasms↗

PubMed2002

Superficial collagenous fibroma: immunohistochemical, ultrastructural, and flow cytometric study of three cases, including one pemphigus vulgaris patient with a dermal mass.

Collagenous fibroma (desmoplastic fibroblastoma) is an extremely rare benign soft tissue tumor of fibroblastic origin. The majority of reported cases have been located in the deep subcutis, fascia, aponeurosis, or skeletal muscle of the extremities, limb girdles, or head and neck regions. There has been no mention of underlying diseases in patients who developed this tumor. We here report an additional three cases of superficial collagenous fibroma, one of which was a dermal lesion occurring in the abdomen of a 26-year-old male patient with a 5-year history of pemphigus vulgaris prior to development of the tumor. To the best of our knowledge, an association between collagenous fibroma and pemphigus vulgaris has not previously been reported. The remaining two tumors were located in the superficial subcutaneous tissue of the infrascapular area and right foot, respectively. There was no tumor recurrence or metastasis during follow up of 18, 25, and 47 months, respectively. All three tumors were well-circumscribed and unencapsulated without infiltrating borders. Histologically, the common denominator of all three cases was paucicellular proliferation of spindle or stellate fibroblasts enmeshed within an extensively collagenous background. Immunohistochemically, there was diffuse strong staining for vimentin and intense focal reaction for smooth muscle actin in two tumors tested. Electron microscopy revealed features consistent with a fibroblastic or myofibroblastic lineage. Flow cytometry in two cases demonstrated a diploid DNA content with low S-phase fractions, which correlated with minimal MIB-1 nuclear labeling (less than 1%) and benign behavior of this entity.

Actins↗

PubMed2002

Tangeretin induces cell-cycle G1 arrest through inhibiting cyclin-dependent kinases 2 and 4 activities as well as elevating Cdk inhibitors p21 and p27 in human colorectal carcinoma cells.

Tangeretin (5,6,7,8,4'-pentamethoxyflavone) is concentrated in the peel of citrus fruits. DNA flow cytometric analysis indicated that tangeretin blocked cell cycle progression at G1 phase in colorectal carcinoma COLO 205 cells. Over a 24 h exposure to tangeretin, the degree of phosphorylation of Rb was decreased after 12 h and G1 arrest developed. The protein expression of cyclins A, D1, and E reduced slightly under the same conditions. Immunocomplex kinase experiments showed that tangeretin inhibited the activities of cyclin-dependent kinases 2 (Cdk2) and 4 (Cdk4) in a dose-dependent manner in the cell-free system. As the cells were exposed to tangeretin (50 microM) over 48 h a gradual loss of both Cdk2 and 4 kinase activities occurred. Tangeretin also increased the content of the Cdk inhibitor p21 protein and this effect correlated with the elevation in p53 levels. In addition, tangeretin also increased the level of the Cdk inhibitor p27 protein within 18 h. These results suggest that tangeretin either exerts its growth-inhibitory effects through modulation of the activities of several key G1 regulatory proteins, such as Cdk2 and Cdk4, or mediates the increase of Cdk inhibitors p21 and p27.

Adenocarcinoma↗

PubMed2002

Obstructive jaundice alters CD44 expression in rat small intestine.

HYPOTHESIS: CD44 is an adhesion molecule expressed by neutrophils, lymphocytes and epithelial cells. CD44 is involved in cell-cell and cell-matrix binding. In addition to lymphocyte trafficking, CD44 also plays a crucial role in the maintenance of intestinal villus integrity. We hypothesize that obstructive jaundice may alter CD44 expression in the rat small intestine and oral glutamine intake can restore the altered CD44 expression in the small intestine of the rat undergoing obstructive jaundice. MATERIALS AND METHODS: In a prospective animal model study at a university hospital, 41 Sprague-Dawley rats were randomized to 4 groups. Group A (n = 13, control) underwent a sham operation. Group B (n = 12, obstructive jaundice for 1 week) underwent common bile duct ligation. Group C (n = 8, obstructive jaundice for 2 weeks) underwent common bile duct ligation. Group D (n = 8, obstructive jaundice for 2 weeks) underwent common bile duct ligation with oral glutamine intake daily. After 1 and 2 weeks, segments of the proximal jejunum and distal ileum were harvested from groups A and B and groups C and D, respectively. Immunohistochemical expression of CD44 on the cell surface was then evaluated and recorded. Comparisons among the 4 groups were performed. RESULTS: In the 1-week obstructive jaundice group, 173.8 +/- 24.0 cells/1,000 enterocytes of the proximal jejunum expressed surface CD44, while 137.0 +/- 13.8 cells were stained in the control group (p < 0.001). In the 1-week obstructive jaundice group, 169.8 +/- 20.7 cells/1,000 enterocytes of the distal ileum expressed surface CD44, while 119.5 +/- 20.8 cells were stained in the control group (p < 0.001). In the 2-week obstructive jaundice group, the number of cells expressing surface CD44 were significantly decreased both in jejunum (112.1 +/- 17.0, p = 0.002) and ileum (100.1 +/- 12.5, p = 0.028) when compared with those of the control group. With daily oral glutamine intake in group D, the number of cells expressing surface CD44 in the jejunum (149.3 +/- 29.7) was restored to that of the control group (p = 0.302) and the number of cells expressing surface CD44 in the ileum (140.4 +/- 23.0) was even higher than that of the control group (p = 0.045). CONCLUSION: Obstructive jaundice for 1 week initially upgraded CD44 expression in the rat small intestine and the CD44 expression later became significantly depressed after obstructive jaundice for 2 weeks. Oral glutamine intake daily could effectively restore the CD44 expression in the small intestine of the rat undergoing obstructive jaundice for 2 weeks.

Animals↗

PubMed2002

Primary yolk sac tumor of the urachus.

Pure yolk sac tumor is the most common malignant gonadal tumor of infants and toddlers. However, the majority of extragonadal germ cell tumors in the midline are either seminomas (germinomas) or teratomas, and pure yolk sac tumors account for only a small fraction of these lesions. To date, only 1 primary urachal pure yolk sac tumor has been reported in the literature. We describe another case, occurring in a 7-month-old male infant who presented with a rapidly enlarging intra-abdominal tumor with marked engorgement of the superficial venous plexus around the umbilicus. With periodic follow-up for 3 years following surgical extirpation of the tumor and adjuvant chemotherapy, this patient is still alive without evidence of disease. Notably, the glandular elements predominating in the frozen sections resulted in the initial misdiagnosis of the tumor as a urachal adenocarcinoma, although the entirely resected specimen revealed typical histologic patterns and Schiller-Duval bodies. Immunohistochemistry showed that the tumor cells were diffusely reactive to alpha-fetoprotein, alpha(1)-antitrypsin, and cytokeratin. Tumor cells were negative for p53 protein, but revealed overexpression for MDM2 protein. Flow cytometry demonstrated a diploid DNA content with S-phase being as high as 55.36%. This case emphasizes that pure yolk sac tumor can occur primarily in the remnant of the urachus in young children.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2002

Solitary infantile myofibromatosis: report of two cases.

Infantile myofibromatosis (IM) is an unusual tumor of infancy and early childhood. It typically presents as a solitary or multicentric nodular mass involving skin, soft tissue, bone, or viscera. We describe 2 cases of solitary infantile myofibromatosis (IM) of the soft tissue with typical light microscopic features. The first is a 7-month-old boy who had a rapidly growing tumor of the right thigh. The fragile tumor, measuring 7.0 x 6.0 x 3.5 cm was completely removed, but the patient was lost to follow-up after surgery. The second case, a 2-year-old boy, was referred from a local clinic due to a non-tender mass in the left abdominal wall. The tumor, measuring 2.0 x 2.0 x 1.6 cm, was completely excised. No recurrence or malignant transformation was found after 22 months of follow-up. The histopathologic, histochemical, and immunohistochemical features of the tumors were studied. Reticulin preparation showed that the tumor cells were outside the reticulin sheath of the vascular spaces and were individually enclosed by reticulin fibers. Tests for vimentin, anti-alpha-smooth muscle actin, and myoglobin were positive in the neoplastic spindle cells. IM has a variable appearance on radiologic images and often mimics an aggressive neoplasm. These factors can make a rapid and correct diagnosis difficult. IM must be considered in the differential diagnosis in any child who presents with either solitary or multiple tumors, particularly those occurring in the neonatal period.

Child, Preschool↗