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Biomedical subjects

A Wee

Publications and source records attributed to A Wee.

108 records · Page 6Linked to original sources
PubMedDate not supplied

Hepatocyte hepatitis B surface antigen expression in chronic hepatitis B virus carriers in Singapore: correlation with viral replication and liver pathology.

The hepatocyte hepatitis B surface antigen (HBsAg) expression in 149 liver biopsies from 124 chronic hepatitis B virus (HBV) carriers was correlated with serum HBV DNA status and histologic activity. Hepatocyte HBsAg was stained by the peroxidase-antiperoxidase method and serum HBV DNA was determined by dot blot hybridization. Sixty-five biopsies (44%) showed minimal changes (MC), 82 biopsies (55%) showed chronic liver disease (CLD) and 2 biopsies (1%) showed hepatocellular carcinoma. Hepatocyte HBsAg was found in 144 biopsies (97%). It was present in the cytoplasm of 141 specimens (95%) and/or plasma membrane of 48 specimens (32%). Approximately half (45%) of the cytoplasmic HBsAg-positive biopsies showed discrete distribution, while the other half (55%) were grouped. Fifty-five per cent (77 of 141) of cytoplasmic HbsAg-positive biopsies had CLD, while 44% (62 of 141) showed MC. There was no relationship between the presence of cytoplasmic HBsAg or its topographic distribution with disease activity. Membrane HBsAg distribution was similar for both groups of patients (MC vs CLD: 25 of 65 (38%) vs 23 of 82 (28%); P = NS). Serum HBV DNA was detected in 98 patients (66%) and was seen mostly in association with CLD (CLD vs MC: 61% vs 39%, P less than 0.001). It was also detected more often in the sera of patients with membrane HBsAg than in those with cytoplasmic HBsAg staining (41 of 48 (85%) vs 97 of 141 (67%); P less than 0.02). However, discrete distribution of cytoplasmic HBsAg was associated with positive serum HBV DNA when compared with grouped distribution (52 of 63 (83%) vs 43 of 78 vs (55%); P less than 0.005).

Carrier State↗
PubMedDate not supplied

Combined hepatocellular-cholangiocarcinoma. Diagnostic challenge in hepatic fine needle aspiration biopsy.

OBJECTIVE: To study the cytohistologic features of combined hepatocellular-cholangiocarcinoma (CHCC-CC) in fine needle aspiration biopsy (FNAB) material. STUDY DESIGN: Six hepatic FNAB cases with cell blocks (five) and hepatic resections (two) were analyzed cytohistologically and immunohistochemically. RESULTS: The six cases were diagnosed as CHCC-CC based on clinicopathologic correlation. Unequivocal hepatocellular carcinoma (HCC) cells corresponding to Edmondson and Steiner's grade 3 lesions were identified in the FNAB in three instances. Adenocarcinoma, represented by cohesive columnar cells with ovoid, basal nuclei displaying nuclear palisading, acini and/or papillary structures with variable intracytoplasmic intraacinar or brush border mucin production, was identified in all cases. Intermediate cells with hybrid/polymorphic cytologic features straddling malignant hepatocytes and glandular cells were identified in five instances. Tissue alpha-fetoprotein was negative. There was brush border and/or diffuse cytoplasmic p-carcinoembryonic antigen immunoreactivity in the glandular elements. CONCLUSION: FNAB diagnosis of CHCC-CC is possible if the clinical, cytohistologic and immunohistochemical findings support the presence of HCC and adenocarcinoma. Intermediate cells pose a great challenge to recognize and define: they tend to lose the classic cytologic features of malignant hepatocytes and acquire glandular characteristics. At the very least, there should be a high index of suspicion. These cases underscore the necessity for clinicopathologic correlation in enhancing the precision of FNAB diagnoses.

Adenocarcinoma↗
PubMedDate not supplied

Fine needle aspiration biopsy of hepatic leiomyosarcoma. An unusual epithelioid variant posing a potential diagnostic pitfall in a hepatocellular carcinoma-prevalent population.

OBJECTIVE: To study the cytomorphologic features of hepatic smooth muscle tumors on fine needle aspiration biopsy (FNAB) material in a hepatocellular carcinoma (HCC)-prevalent population, in which a potential diagnostic pitfall is an unusual variant of metastatic epithelioid leiomyosarcoma seen on aspiration cytology. STUDY DESIGN: FNABs of five cases of metastatic hepatic leiomyosarcomas were studied cytohistologically and immunocytochemically. In addition, ultrastructural studies were performed in one unusual case. Resected hepatic specimens and all other relevant histopathologic specimens were reviewed. RESULTS: Classically, aspirates of leiomyosarcoma produced syncytial masses of spindle cells characterized by overlapping, cigar-shaped nuclei and truncated ends. An unusual variant of metastatic epitheliod leiomyosarcoma was studied, with cytohistologic, immunohistochemical and ultrastructural correlation. CONCLUSION: Hepatic spindle cell lesions consist mainly of metastatic leiomyosarcomas. The diagnosis of malignancy and metastatic status of hepatic smooth muscle tumors is facilitated by the presence of an extrahepatic primary tumor. In a hepatitis B virus-endemic population, HCC, sarcomatoid type, has to be considered in the differential diagnosis of hepatic spindle cell lesions and the classic type, in epithelioid variants of smooth muscle tumors.

Adult↗
PubMedDate not supplied

pCEA canalicular immunostaining in fine needle aspiration biopsy diagnosis of hepatocellular carcinoma.

OBJECTIVE: To assess the usefulness of bile canalicular polyclonal carcinoembryonic antigen (pCEA) immunostaining in fine needle aspiration biopsy (FNAB) diagnosis of hepatocellular carcinoma (HCC). STUDY DESIGN: Hepatic FNAB with cell blocks of 72 confirmed and 6 possible HCC and 23 non-HCC malignancies (controls) were analyzed. Sections were stained with antibody to pCEA using the streptavidin biotin-immunoperoxidase method and results correlated with tumor grade and other parameters used in HCC diagnosis. RESULTS: Canalicular pCEA staining was observed in 60 (83%) of the 72 HCC. This category comprised 29%, 31%, 36% and 4% grade 1-4 tumors, including 7 small cell, 4 clear cell and 1 giant cell variants. With increasing anaplasia, the canaliculi became infrequent, irregularly distributed, and increasingly distorted and interrupted. Canalicular staining helped distinguish clear and small cell variants from metastatic renal cell carcinomas and neuroendocrine tumors, respectively. Of the six problematic cases, one was confirmed to be HCC with plasmacytoid features and five to be adenocarcinomas, of which three could have been combined hepatocellular-cholangiocarcinomas. Liver cell dysplasia also displayed an abnormal canalicular pattern. No cytoplasmic staining was seen in pure HCC. CONCLUSION: pCEA immunostaining cannot separate malignant, dysplastic or benign hepatocytes. It is usually not required in cytodiagnosis of most HCC. However, it is most helpful in confirming atypical variants of HCC, which may mimic other tumors.

Adenocarcinoma↗
PubMedDate not supplied

Fine needle aspiration biopsy of small/intermediate cell tumors in the liver. Considerations in a southeast Asian population.

OBJECTIVE: To assess the diagnostic problems and accuracy involved in rendering an exact cytologic diagnosis, including reference to a primary site of origin, on fine needle aspiration biopsies (FNABs) of small/intermediate cell tumors of the liver. STUDY DESIGN: Thirty-five hepatic FNABs of small/ intermediate tumors, neuroendocrine tumors (NETs) and poorly differentiated or undifferentiated cancers occurring in adults were analyzed. Ancillary studies, including immunohistochemistry, were performed whenever necessary. All other relevant histopathologic sections and medical records were reviewed. RESULTS: There were 26 metastases, while 9 were considered primary lesions. The aspirates were categorized into 11 NETs (pancreas 5, lung 1, liver 2, unknown primary 3); 9 undifferentiated nasopharyngeal carcinomas; 2 small cell undifferentiated carcinomas (lung 2); 4 undifferentiated carcinomas, not otherwise specified (lung 1, pancreas 1, liver 1, unknown 1); 1 lobular-ductal carcinoma (breast); 1 glioblastoma multiforme (brain); 1 ovarian carcinoma; 1 non-Hodgkin's lymphoma (liver); and 5 primary hepatocellular carcinomas. CONCLUSION: There was histologic and/or immunohistochemical confirmation in 25 cases (71%). Some of the limitations in categorization of such tumors obtained by FNAB can be overcome by immunohistochemistry. Information gleaned from a precise cytologic diagnosis can sometimes only favor a particular primary site.

Adult↗
PubMedDate not supplied

Bilateral carcinoid tumor of the breast. Report of a case with diagnosis by fine needle aspiration cytology.

A case of bilateral carcinoid tumors of the breast was studied by cytology, histology, immunohistochemistry and electron microscopy. The preoperative aspiration cytologic findings strongly suggested a carcinoid tumor of the breast. The differential diagnosis with fine needle aspiration cytology of other breast lesions, the bilaterality of the condition and terminology are discussed.

Biopsy, Needle↗
PubMedDate not supplied

Fine needle aspiration biopsy of hepatocellular carcinoma. Some unusual features.

The cytologic features of fine needle aspiration smears from 28 hepatocellular carcinomas (HCC) were reviewed. All aspirations except one were guided. There were 14 well-, 11 moderately and 3 poorly differentiated HCC. The better-differentiated HCC were characterized by similarity of the tumor cells to hepatocytes (83%), cohesive cell clusters with a trabecular arrangement (72%) and presence of sinusoidal endothelial cells (66%). Other features included bile production (38%), atypical hepatocytic naked nuclei (52%), acinar formation (31%), intracytoplasmic vacuoles (14%) and abnormal vascular patterns (14%). Poorly differentiated HCC showed dyshesive pleomorphic cells. Unusual cytologic features from a well-differentiated HCC with fatty change and an HCC with a prominent acinar component are described. The identification of fatty change in dissociated well-differentiated hepatocytes or cytologic features suggestive of an adenocarcinoma do not preclude the diagnosis of HCC. The usefulness of cell blocks is emphasized.

Adult↗
PubMedDate not supplied

Fine needle aspiration biopsy of hepatocellular carcinoma. Diagnostic dilemma at the ends of the spectrum.

A diagnostic dilemma exists at the extreme ends of the spectrum in the cytodiagnosis of hepatocellular carcinoma (HCC). The cytologic features of fine needle aspiration biopsies from 30 well- and 16 poorly differentiated HCC were reviewed and the adjunctive role of serum alpha-fetoprotein (AFP), hepatitis B virus (HBV) markers and radiologic findings evaluated. Some subtle features noted in very well differentiated HCC include small tumor cell size with increased nuclear/cytoplasmic ratio, monotony of atypia, hepatocytic tumor giant cells and narrow trabeculae with tendency for cell dissociation. Useful features in poorly differentiated HCC include cell dehiscence, large cells with ovoid nuclei and thickened nuclear membranes, and one or more increasingly prominent nucleoli, with some assuming a reniform configuration. The serum AFP levels are not always elevated. Positive HBV markers, cirrhosis and compatible imaging findings are suggestive but not diagnostic. The general inclination, however, is still toward a diagnosis of HCC if the aspirate is from a focal lesion or lesions in a hepatitis B surface antigen-positive, cirrhotic liver. Cell block sections provide histologic confirmation.

Adult↗
PubMedDate not supplied

Bile cytology. Diagnostic role in the management of biliary obstruction.

Thirty satisfactory bile specimens from 21 patients (13 with cancer and 8 with benign conditions) were reviewed to assess the diagnostic role of bile cytology in the management of biliary obstruction. Smears were malignant in 5 instances, suspicious in 1, atypical in 2 (8 in the positive group) and negative in 22. There were no false positives. The diagnostic sensitivity was 38%, specificity 100% and overall accuracy 57%. Of interest were (1) hepatocellular carcinoma, causing obstruction in three patients; (2) metastatic colonic adenocarcinoma, causing obstruction in another instance; (3) positive cytodiagnosis in a patient who developed biliary stricture following laparoscopic cholecystectomy; and (4) detection of acidfast bacilli in bile from a case of tuberculous pseudotumor mimicking a hepatic malignancy. Bile cytology is a simple, inexpensive means of obtaining tissue confirmation of neoplastic and specific inflammatory causes of biliary obstruction. It is a useful adjunct to other techniques in this era of fiberoptic diagnostic procedures. Cell block sections should be prepared whenever possible.

Adult↗
PubMedDate not supplied

Aspiration cytology of liver abscesses. With an emphasis on diagnostic pitfalls.

Clinical and imaging features of liver abscesses are not specific. Necrotic hepatic neoplasms, primary or secondary, can mimic abscesses, and vice versa. Thirty-eight patients who had cytologic confirmed abscesses were analyzed. There was clinical, radiologic and cytologic concurrence in 27 patients. In six cases the clinically suspicious lesion turned out to be inflammatory. The remaining five were malignant. There were four amebic and three tuberculous cases in this series. Cytologically, pyogenic abscesses contained a heavy, neutrophilic, inflammatory exudate with nuclear debris. By comparison, amebic cases contained more necrotic debris, with degenerating hepatocytes and fewer inflammatory cells. Acid-fast bacilli were identified in two tuberculous abscesses; however, only one contained caseous necrotic material and epithelioid cells. A potential pitfall in the cytologic diagnosis of a case of inflammatory pseudotumor is emphasized. The diagnosis of liver abscess should be established by clinical and imaging findings in conjunction with needle aspiration.

Adult↗
PubMedDate not supplied

Tuberculous pseudotumor causing biliary obstruction. Report of a case with diagnosis by fine needle aspiration biopsy and bile cytology.

Hepatobiliary tuberculosis is a rare but distinct clinical entity. We report an unusual case of biliary tract obstruction due to localized hepatic tuberculosis with periportal tuberculous adenitis. The lesion mimicked a malignancy clinically and radiologically. Fine needle aspiration biopsy revealed granulomas, epithelioid histiocytes and Langhans' giant cells. The cytodiagnosis was confirmed by identification of acid-fast bacilli in the bile cytology and isolation of Mycobacterium tuberculosis by culture. The patient responded to antituberculosis therapy. The usefulness of bile cytology in the diagnostic management of biliary tract obstruction is illustrated.

Bile↗
PubMedDate not supplied

Characterization of p53 gene mutations in colorectal carcinomas from an Asian population.

A series of colorectal carcinomas from an Asian population in Singapore were analyzed for mutations in the tumor suppressor gene p53. Based on single-strand conformation polymorphism (PCR-SSCP) analysis and direct DNA sequencing, 15 of 38 tumors (39%) were found to contain mutations in exons 5-8 of the p53 gene. The point mutations were predominantly base transitions. Among the 10 transitions, 5 were at CpG dinucleotide sites. One-third (5/15) of the mutations were found at previously identified hotspot codons 175, 248 and 282. In one case, an insertion of a 6-base pair sequence was found. p53 mutations did not correlate with tumor histological grade, Dukes' stage, or metastases. However, tumors at the distal site showed a higher proportion of mutations than the proximal site. Further, no mutation was found in the normal mucosa adjacent to tumor site, suggesting that no germ-line mutations were present. The results were compared with those from other studies and are discussed in connection to possible etiological factors that are specific to the local population.

Amino Acid Sequence↗
PubMedDate not supplied

Retroperitoneal endodermal sinus tumor. Report of a case with an abnormal cervicovaginal smear.

An unusual case of an endodermal sinus tumor arising in the retroperitoneum and invading the fallopian tube is reported. The patient presented with malignant cells mimicking adenocarcinoma in the cervicovaginal smear. The differential diagnoses of such cells in cervicovaginal cytology are discussed. The cytohistologic, immunohistochemical and ultrastructural findings of the tumor are correlated.

Adult↗
PubMedDate not supplied

Adenomyoepithelioma of the breast. Report of a case with fine needle aspiration cytology and histologic, immunohistochemical and ultrastructural correlation.

A case of adenomyoepithelioma of the breast was studied by cytology, histology, immunohistochemistry and electron microscopy. Aspiration cytology of the tumor showed sheets and tubular-type clusters of cohesive, regular polygonal cells with abundant, fairly well preserved, pale, granular to finely vacuolated, clear cytoplasma and a low nuclear/cytoplasmic ratio. The nuclei were small, round and monotonous, with dispersed chromatin and small or inconspicuous nucleoli. Acinus formation was striking: an occasional gland showed a suggestion of an inner layer of cells with denser cytoplasm surrounded by an outer mantle of paler cells. The histologic, immunohistochemical and ultrastructural findings confirmed the two cell populations, constituting an inner epithelial and outer myoepithelial component, both participating in the neoplastic process. The differential diagnoses of various breast lesions with somewhat similar cytologic features are discussed.

Aged↗
PubMedDate not supplied

Biliary cystadenocarcinoma arising in a cystadenoma. Report of a case diagnosed by fine needle aspiration cytology.

Hepatic cyst fluid cytology tends to yield disappointing results. We report a case of a 56-year-old woman with a biliary cystadenocarcinoma diagnosed by fine needle aspiration cytology. Computed tomography scans had shown a solitary, unilocular hepatic cyst over a five-year period. There was a recent increase in the size and development of a mural echogenic focus. Cytologic examination revealed clusters of malignant glandular cells in a background of cellular debris and mucinophages. The resected specimen confirmed the presence of an adenocarcinoma arising from malignant transformation of a preexisting cystadenoma.

Adenoma, Bile Duct↗