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Michal Michal

Publications and source records attributed to Michal Michal.

89 records · Page 5Linked to original sources
PubMed2003

Vanek's tumor (inflammatory fibroid polyp). Report of 18 cases and comparison with three cases of original Vanek's series.

Eighteen cases of Vanek's tumors are presented. The patients included nine men and nine women between the ages of 45 and 93 years (mean, 66.2 years). Nine cases were clinically diagnosed as polyps of the gastric antrum, five cases as polyps of the stomach (not otherwise specified), one polyp was located in the ileum and the three remaining polyps in the small intestine (not otherwise specified). The thirteen polyps with available size information measured from 0.4 to 5 cm in the greatest diameter (mean, 2.2 cm). Immunohistochemically, the affections were positive for vimentin (18/18) and CD34 (15/18). All the cases negative for CD34 also lacked concentric onion skin-like formations of the spindle cells around glands and vessels. The different immunophenotype and absence of concentric formations could be explained by the existence of two different lesions commonly designated as Vanek's tumor (inflammatory fibroid polyp) or by the hypothesis of various evolutional stages. In the differential diagnosis, it is important to distinguish namely eosinophilic gastroenteritis, gastrointestinal stromal tumor, inflammatory pseudotumor, hemangioendothelioma, and hemangiopericytoma. In contrast to gastrointestinal stromal tumors, genetically no substitution, deletion, or insertion occurred in c-kit exon 11 in all analyzed samples. Likewise, no deletion or insertion in part of c-kit exon 9 was observed.

Aged↗
PubMed2003

KIT 1530ins6 mutation defines a subset of predominantly malignant gastrointestinal stromal tumors of intestinal origin.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. GISTs express KIT and show gain-of-function KIT mutations. Most of these mutations affect the KIT juxtamembrane domain, but other KIT domains are mutated at a lower frequency. In this study, frequency of GCC TAT insertion mutation (1530ins6) in KIT exon 9 (extracellular domain) and its possible clinicopathologic significance was investigated. Screening of 520 GISTs identified 26 cases with 1530ins6 KIT mutation and confirmed the previously reported low frequency of this type of KIT mutation among GISTs of different locations. Of the 26 tumors with 1530ins6 KIT mutation studied, 21 originated from the small intestine, 1 from the colon, and 3 from the rectum. In 1 case, primary small intestinal versus colonic localization could not be clearly established because of intra-abdominal dissemination. No distinctive morphological features were identified for the cohort of tumors defined by 1530ins6 KIT mutations. Most of the tumors showed predominant spindle cell morphology, and a few cases had epithelioid or pleomorphic histological features. Following previously published criteria based on tumor size and mitotic rate, 22 of 26 (85%) tumors were classified as malignant or potentially malignant, and 4 (15%) were classified as probably benign. A malignant clinical course was documented in 18 of 19 tumors from the malignant category. The survival times of 11 patients who died of disseminated GISTs ranged from 1 month to 105 months (median survival time, 26 months). In contrast, 2 of 4 GISTs assigned as probably benign tumors with follow-up information had long disease-free survival. GISTs carrying 1530ins6 occur exclusively in the intestinal location, and a great majority of these tumors follow a malignant course.

Adult↗
PubMed2003

Thread-like bridging strands: a morphologic feature present in all adenomatoid tumors.

Adenomatoid tumor (AT) is a benign, relatively rare neoplasm occurring primarily in the genital tract of both genders. Histologically, ATs were composed of fibrous tissue, which are separated by numerous slit-like and pseudotubular spaces. Peculiar "thread-like bridging strands" (TBS) crossing the pseudotubular spaces are typical morphologic feature. In this study, the frequency of occurrence of these TBS within a large series of ATs in various organs was examined. Sixty-nine cases were included in our study. Twenty-eight cases occurred in women, 41 cases in men. Tumors were located in the myometrium, fallopian tube, ovary, epididymis, tunica albuginea, and testicular parenchyma. Tumor size ranged from 0.8 to 8.2 cm (mean, 2.7 cm). TBS were found in 100% of cases. Presence of thin intraluminal TBS within ATs was a constant morphologic feature independently on gender and localization of the lesions. Ultrastructurally, they were always formed by apposition of attenuated cytoplasm of two adjacent mesothelial cells. In our opinion, TBS are morphologically very specific for ATs and we are not aware of any other epithelial structure in any organ demonstrating as appearance similar to these TBS of ATs.

Adenomatoid Tumor↗
PubMed2003

Metanephric adenoma and papillary carcinoma with sarcomatoid dedifferentiation of kidney. A case report.

We present the case of a 74-year-old Caucasian male with an expansive process of the left kidney. No clinical and laboratory signs of polycytemia or hypertension were present. Microscopically, the spherical main tumor mass was composed of small basophilic cells arranged in longitudinal branching tubules typical of metanephric adenoma (MA). Another component, different from MA, was formed by a tumor in a papillary and tubopapillary arrangement. This component was diagnostic of grade 3 papillary renal cell carcinoma. The third component, which was merging with the papillary one, was composed of sarcomatoid, spindle cell carcinoma with prominent nuclear polymorphism and a high number of mitotic figures, including atypical mitoses. The sarcomatoid component filled the entire cortico-medullary space and infiltrated the surrounding non-neoplastic renal tissue, including the renal pelvis. Areas of necroses, hemorrhages, and mitotic figures were frequent. No structures of Wilm's tumor were seen in our case. One year after the excision, the patient is without recurrence and metastasis. The existence of the above mentioned tumor supports the hypothesis that metanephric adenomas and papillary renal cell carcinomas are interrelated lesions.

Adenoma↗
PubMed2003

Neuroendocrine carcinomas (carcinoid tumor) of the testis. A clinicopathologic and immunohistochemical study of ten cases.

We studied 10 cases of primary pure testicular neuroendocrine carcinoma. Patients were between 16 and 48 years old and had testicular swelling with pain or a painless testicular mass and no history of neuroendocrine carcinoma or other malignant neoplasm. All underwent orchiectomy. The tumors were low (n = 9) and intermediate (n = 1) grades with a variegated histologic appearance characterized by a nesting pattern, cords of neoplastic cells with rosettes, or sheets of neoplastic cells. Mitotic activity was lacking in 9 cases. In 1 case, mitotic figures ranged from 7 to 8 per 10 high-power fields, and cellular atypia and comedo-like necrosis were present. Immunohistochemical studies using a keratin cocktail, chromogranin, synaptophysin, epidermal growth factor, p53, placental-like alkaline phosphatase, and CD117 (c-kit) were performed in all cases. Keratin, chromogranin, and synaptophysin were positive in all tumors. Clinical follow-up information was obtained for 6 patients (range, 12-60 months): 5 with low-grade tumors were alive 24 to 60 months after diagnosis; 1 with an intermediate-grade tumor died of tumor 12 months after initial diagnosis. The behavior of these tumors, while in the testicular region, correlates well with the histologic grade. We propose replacing the term testicular carcinoid with neuroendocrine carcinoma, which better reflects the nature of these neoplasms.

Adolescent↗
PubMed2002

Spindle cell lipoma-like tumor, solitary fibrous tumor and myofibroblastoma of the breast: a clinico-pathological analysis of 13 cases in favor of a unifying histogenetic concept.

We reviewed the clinico-pathological features of a series of 13 cases of benign spindle stromal tumors (BSSTs) of the breast relating to a basic common theme consisting of a well-circumscribed proliferation of vimentin+/CD34+/BCL-2+/CD99+ spindly to oval-epithelioid cells, variably arranged in haphazard to short fascicular growth pattern, with interspersed thick or thin collagen bands. Morphological variations included atypical mono- or multi-nucleated cells in five cases and a mature lipomatous tumor component, varying from focal to prominent, in eight cases. Based on morphological and immunophenotypical features, a distinction was made between two main subtypes of these tumors--fibroblastic and myofibroblastic. The former subtype included two cases respectively represented by a typical solitary fibrous tumor (SFT) and a neoplasm labeled "spindle-cell lipoma (SCL)-like tumor", closely reminiscent of soft tissue SCL. Both tumors had cells with fibroblastic-like appearance, haphazardly arranged and immunoreactive for vimentin, CD34, BCL-2, and CD99. The latter subtype, comprised nine cases exhibiting evidence of myofibroblastic differentiation (desmin and alpha-smooth muscle actin) which were classified as myofibroblastomas (MFBs). The remaining two cases were defined as "mixed BSSTs", having typical features of diverse neoplasms, respectively represented by a case of MFB with focal SFT and pleomorphic/SCL-like areas, and SFT with focal MFB-like component. The common basic morpho-immunophenotypical features, the possibility that both fibroblastic and myofibroblastic tumors may contain an additional mature lipomatous component, and the existence of hybrid stages (mixed BSSTs) strongly support the view that such tumors belong to the same category of lesions. We postulate that the precursor of all these neoplasms is the vimentin+/CD34+ cells of the mammary stroma, the well-known inherent plasticity of which to differentiate toward several mesenchymal lines, provides the explanation for the phenotypic heterogeneity of these neoplasms. Accordingly, the encompassing term "benign spindle stromal tumors of the breast" is advocated for such tumors.

12E7 Antigen↗
PubMed2002

Epithelial plasma cell granuloma-like tumors of the lungs. A hitherto unrecognized tumor.

We present two cases of benign pulmonary epithelial tumors located in the middle lobes of the lungs. The patients were women of 56 and 36 years of age. The tumors were morphologically similar to plasma cell granuloma. At the tumor periphery, the lesion cells formed thin organoid rows of cells and vague trabeculae, disclosing morphologically their epithelial nature. In addition, the tumors strongly stained immunohistochemically with antibodies to cytokeratins, TTF-1 and EMA, and they were negative for immunoglobulin kappa and lambda light chains. We are not aware of similar tumors described in the literature, and we suggest the name "epithelial plasma cell granuloma-like tumors" for these lesions.

Adult↗
PubMed2002

Inflammatory myxohyaline tumor with massive emperipolesis.

We report on a 36-year-old man with a recurrent mass on the thenar side of the right hand. Against the background of dense inflammation, inflammatory malignant fibrous histiocytoma was first diagnosed, but typical morphologic features in the recurrent tumor led to a correction of the diagnosis--inflammatory myxohyaline tumor. Massive emperipolesis of the neoplastic cells, forming the so-called "cell microabscesses", dominated the histologic picture in both primary and recurrent lesions. Awareness of this unique feature helps in differentiating this entity from both benign inflammatory processes and clearly malignant tumors.

Adult↗
PubMed2002

Dermatofibrosarcoma protuberans with EMa+ cells. Report of a case suggesting perineurial cell differentiation.

A case of dermatofibrosarcoma protuberans (DFSP) with epithelial membrane antigen (EMA)-positive cells is described. The tumor was excised from the left groin of a 28-year-old woman. It showed characteristic histologic features of DFSP with typical diffuse immunohistochemical positivity for CD34. Moreover, scattered neoplastic cells expressed EMA, suggesting perineural cell differentiation. Ultrastructural study found perineurial cell features, such as thin long bipolar cytoplasmic processes, pinocytotic vesicles, fragments of external lamina and/or external lamina-like material, attachment plaques, and desmosome-like junctions. This observation, together with previous immunohistochemical findings of EMA-positive cells in a subset of DFSPs, strongly suggests perineurial cell differentiation in these tumors. DFSP should be included in the differential diagnosis of EMA-positive spindle cell lesions of superficial soft tissue and skin.

Adult↗
PubMed2002

Gigantic cutaneous horns of the scalp: lesions with a gross similarity to the horns of animals: a report of four cases.

Gigantic cutaneous horns, grossly similar to the horns seen in animals, are exceedingly rare in humans. After finding one case in practice, we searched our departmental files for similar cases and examined them grossly and microscopically. Four cases were identified. All occurred as solitary lesions in older women on the parietal-occipital region of the scalp. They had a growth history of up to 30 years; the women hid these horns in their hair. Grossly, the horns were yellow-grey, and there were shallow furrows running along the length of the horns. The length ranged from 17 to 25 cm, and the width was up to 2.5 cm. All four lesions showed similar histologic changes. Microscopically, the gigantic horns consisted of a mixture of squamous epithelial cells and tricholemmal keratinized debris. In one case the base of the horn was directly connected with a mass composed of benign tricholemmal cysts of the scalp. Mitoses were common, but atypical mitoses were not observed. The nuclei of the squamous cells were bland without pleomorphism, hyperchromasia, or atypia. Follow-up of all patients was uneventful: all patients were well and without signs of recurrence or metastasis 2-15 years after the surgical excision. Gigantic cutaneous horns are rare and benign. We think that they represent an extremely well-differentiated variant of proliferating tricholemmal tumor with an unusual and remarkable gross pattern.

Aged↗
PubMed2002

Plexiform xanthomatous tumor: a report of 20 cases in 12 patients.

We present 12 patients with 20 plexiform xanthomatous tumors (PXTs). All patients were male. Patient ages ranged from 20 to 59 years (mean 45 years). Clinical information was available for 11 (92%) patients. Only one patient with markedly elevated cholesterol levels had a family history of hypercholesterolemia; none of the others had a family or personal history of diabetes mellitus, hypercholesterolemia, or hyperlipoproteinemia. Three patients had markedly elevated serum triglyceride levels. The tumors were solitary in seven patients and multiple in five patients: three patients had two tumors, one presented had three, and one had four. PXTs were located on the knee (n = 8), elbow (n = 5), foot or hand (n = 3), and one each on the Achilles tendon, buttock, toe, and back. PXT was white to yellow in color and ranged in size from 0.7 to 5 cm (mean 2.7 cm). The tumors were located in the dermis and subcutis, had a distinctive plexiform arrangement, and were composed of various admixtures of uniform epithelioid and xanthomatous cells. All tumors in patients with solitary or multiple lesions had a plexiform architecture. Most of the nodules of the plexiform pattern of PXTs measured 0.5-2 mm. Rarely cholesterol clefts, necrosis, sparse inflammation, and multinucleated Touton giant cells were present. In two patients with multiple tumors, the PXT completely lacked the xanthoma cells and thus resembled an epithelioid lesion. Immunohistochemically, all lesions were KP1 (CD68) and vimentin positive and lysozyme, S-100 protein, HMB-45, epithelial membrane antigen, cytokeratins, factor VIIIrag, CD34, muscle-specific actin, alpha-smooth muscle actin, desmin (D33), desmin (Der-11), chromogranin, synaptophysin, neurofilament protein, and glial fibrillary acidic protein negative. Two patients with multiple lesions noted recurrences over 10 years. With the exception of one patient who died of an unknown cause, all 10 patients with follow-up were alive, some with residual disease, over a mean of 9 years (range 1-25 years). Some PXTs may represent a morphologic variant of tuberous or tendinous xanthoma, yet its exclusive occurrence in men, absence of personal/familial hyperlipemia/hypercholesterolemia in some patients, and relative paucity of inflammation and cholesterol clefts may make this a distinctive entity.

Adult↗
PubMed2002

Renal pelvic carcinoma with unusual appearance simulating amyloidosis (myeloma kidney): a report of five cases.

We describe 5 cases of urothelial carcinoma (UC) of the renal pelvis, which grew in a distinctive gross and microscopical pattern into the renal parenchyma. Five patients (2 men and 3 women, mean age 67.4 years) underwent nephrectomy for vague clinical findings. The cut surface of the tumor was white to light gray and the consistency was elastic. The corticomedullary border was indistinct, resulting in an appearance that suggested amyloidosis or myeloma. The renal pelvis showed normal mucosa with areas of dysplastic changes. The tumors spread from the renal pelvis in a diffuse and irregular, infiltrative pattern and surrounded intact glomeruli. Detailed sampling of invasive tumor component showed foci of UC with transitions to clear squamous cells. The predominant clear squamous neoplastic cells had foci of granular eosinophilic cytoplasm and resembled conventional renal cell carcinoma. Four patients were alive and without signs of the disease for 5 months to 4 years after nephrectomy; 1 died of generalized tumor 7 months after nephrectomy. The unusual gross and microscopic features result in varied problems in differential diagnosis, which are discussed herein.

Aged↗
PubMed2000

Hyalinized Uterine Mesenchymal Neoplasms with HMB-45-Positive Epithelioid Cells: Epithelioid Leiomyomas or Angiomyolipomas? Report of Four Cases.

We present 4 cases of uterine mesenchymal tumors that were located mostly in the myometrium in middle-aged women. Grossly the tumors vaguely resembled conventional leiomyomas. All tumors were extremely hyalinized. The tumor cells were remarkable because of their large size and epithelioid shape. They occurred singly or more often in variously sized clusters with pericellular clear spaces looking like a halo. The extracellular matrix often formed lacunae around the neoplastic cells. The lacunar type of growth was somewhat reminiscent of immature cartilage. In some places the cells lined up in vague cord-like structures. The epithelioid cells often grew within vessel walls and subendothelially, simulating angioinvasion. In 2 cases there were periodic acid-Schiff (PAS)-positive, needle-shaped crystalloids in the cytoplasm of the tumor cells. No atypias and no mitoses were found in any of the 4 tumors. Mucicarmine stain was negative in all cases. Immunohistochemically the tumor cells were negative for cytokeratins, synaptophysin, chromogranin, epithelial membrane antigen (EMA) S-100 protein, and inhibin. They were instead strongly positive for smooth muscle actin, desmin and HMB-45. All patients are disease free after a 1-4-year follow-up. Int J Surg Pathol 8(4):323-328, 2000

Journal Article↗