The distinction of carcinomas involving periampullary region is often difficult, even in the surgically resected specimens. To examine the differences in the expressions of cytokeratin (CK) 7 and 20 in the periampullary carcinomas, we performed immunohistochemical studies on surgically resected 20 pancreatic duct adenocarcinomas (PDA), 13 distal bile duct adenocarcinomas (DBA), 10 duodenal adenocarcinomas (DA), and 18 ampulla of Vater adenocarcinomas (AVA). We analyzed the relationships between CK 7/CK 20 immunoprofile, and tumor cell differentiation and tumor size. We interpreted diffuse cytoplasmic reactivity found in > or =5% of tumor cells as positive. In the majority of cases, PDA were CK 7 /20 (95%), DBA CK 7 /20 (92.3%), DA either CK 7 /20 (40%) or CK 7 /20 (30%), AVA either CK 7 /20 (50%) or CK 7 /20 (44.4%). In DA, there was an increased CK 20 negativity in less differentiated (moderately or poorly differentiated) cases (p<0.05) and in larger (> or =5 cm) tumor size (p=0.049). In AVA, there was a tendency of increased CK 20 positivity in less differentiated cases (p=0.10). In conclusion, the CK 7/CK 20 immunophenotype is useful in the differentiation of periampullary carcinomas: the CK 7 /CK 20 immunophenotype strongly suggests DA or AVA, whereas the CK 7 /CK 20 immunophenotype suggests PDA or DBA.
Adenocarcinoma ; Ampulla of Vater ; Bile Ducts ; Cell Differentiation ; Cytoplasm ; Keratin-20 ; Keratin-7* ; Keratins* ; Pancreatic Ducts

BACKGROUND: Micropapillary urothelial carcinoma of urinary bladder is a rare and aggressive subtype of urothelial carcinoma (UC). METHODS AND RESULTS: Seven UCs with a micropapillary component (MPC) were identified by reviewing 135 cystectomy specimens of UC (5.2% in incidence). MPC was associated with conventional UC in 6 cases and the plasmacytoid variant of UC in 1 case. Lymph node metastasis, that characteristically contained MPC was present in 60% (3 out of 5 cases of regional lymph node dissection). Three patients with extensive MPC showed laminar propria invasion (pT1; 33%) and perivesical fat invasion (pT3; 67%). Two out of 3 patients with extensive MPC showed distant metastasis into the colon after cystectomy. The colonic lesions showed exclusively micropapillary differentiation. Four patients with focal or moderate MPC (pT2, 25%; pT3, 75%) were alive without disease at the time of writing this article. All 3 cases with extensive MPC had surface and/or invasive MPC on the prior TURB specimen. Immunohistochemically, the tumor cells were positive for cytokeratin 7, cytokeratin 20, EMA and E-cadherin and tissue retraction spaces that simulate lymphatic spaces were negative for CD34 in all 7 cases. CONCLUSIONS: This study suggests that the micropapillary growth pattern in UC is a manifestation of aggressive behavior and UC with MPC must be included as part of the differential diagnosis when dealing with a metastatic lesion with a micropaillary structure.
Cadherins ; Colon ; Cystectomy ; Diagnosis, Differential ; Humans ; Keratin-20 ; Keratin-7 ; Lymph Nodes ; Neoplasm Metastasis ; Urinary Bladder ; Writing

The distinction between cholangiocarcinoma (CC) and metastatic colonic adenocarcinoma of the liver (MCA) is often difficult, particularly in needle biopsy and fine-needle aspiration specimens, if histologic features alone are used. To examine the differences in the expressions of the cytokeratin (CK) 7 and 20 in the CCs and MCAs, we performed immunohistochemical studies on surgically resected 19 CCs and 23 MCAs. We used monoclonal antibodies against CK 7 and CK 20, and applied microwave antigen retrieval technique on formalin-fixed, paraffin-embedded tissue. We interpreted diffuse cytoplasmic reactivity found in > or =5% of tumor cells as positive. CCs showed CK 7+/CK 20- immunophenotype in 63%, CK 7+/CK 20+ in 32%, CK 7-/CK 20+ in 5%, and CK 7-/CK 20- in 0%. MCAs exhibited CK 7-/CK 20+ immunophenotype in 87%, CK 7+/CK 20+ in 9%, CK 7-/CK 20- in 4%, and CK 7+/CK 20- in 0%. CK 20-reactive cells in CCs were frequently columnar in shape (p<0.05). In conclusion, the CK 7/CK 20 immunophenotype was useful in the differentiation of CCs from MCAs: the CK 7+/CK 20- immunophenotype strongly suggested CCs, whereas the CK 7-/CK 20+ immunophenotype strongly suggested MCAs.
Adenocarcinoma* ; Antibodies, Monoclonal ; Biopsy, Fine-Needle ; Biopsy, Needle ; Cholangiocarcinoma* ; Colon* ; Cytoplasm ; Keratin-20 ; Keratin-7 ; Keratins* ; Liver* ; Microwaves

Low-grade adenocarcinomas that primarily arise within the sinonasal tract are uncommon tumors. We report here on three cases of primary sinonasal low-grade adenocarcinomas. The patients were 2 females and 1 male with ages of 48, 57 and 64, respectively. Microscopically, the tumors had a well developed tubulopapillary growth pattern that consisted of columnar or pseudostratified cells with eosinophilic cytoplasm, round to oval nuclei and rare mitotic activity. On immunohistochemistry, the tumor cells were strongly positive for cytokeratin 7, but they were negative for cytokeratin 20, CDX-2 and p53. The Ki-67 labeling index was very low (mean: 1.9%). Two patients developed recurrent tumors at the primary site after the initial surgery, but all the patients are presently alive without metastasis 6 years 8 months, 8 years 8 months, and 11 months after the initial diagnosis. When considering the progress of these tumors, we think that it's important to understand the pathology of this entity to avoid underdiagnosis because a complete excision is required for effective treatment.
Adenocarcinoma* ; Cytoplasm ; Diagnosis ; Eosinophils ; Female ; Humans ; Immunohistochemistry ; Keratin-20 ; Keratin-7 ; Ki-67 Antigen ; Male ; Neoplasm Metastasis ; Pathology

Extramammary Paget's disease (EMPD) typically presents as an eczematous, eroded or crusted plaque. Only a few cases with depigmentation have been reported. We herein report a patient with a depigmented scrotal patch as the sole finding of EMPD. Since he had concurrent rectal cancer, we stained the tissue with gross cystic disease fluid protein-15 (GCDFP-15) and cytokeratin 20 (CK20) in order to differentiate primary/secondary EMPD. This case represents coincidental primary EMPD and rectal cancer, of which the initial features of EMPD were unusual.
Adenocarcinoma* ; Cytochrome P-450 CYP1A1 ; Humans ; Keratin-20 ; Paget Disease, Extramammary* ; Rectal Neoplasms*

PURPOSE: This study was aimed at evaluating the diagnostic validity of peritoneal dissemination of gastric cancer cells by performing multiple genetic marker analysis via quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) in gastric cancer cell lines and gastric cancer tissues. MATERIALS AND METHODS: Quantitative RT-PCR was performed on 12 human gastric cancer cell lines and 10 gastric cancer tissues with four mRNAs of carcinoembryonic antigen (CEA), Cytokeratin 20 (CK20), dopa decarboxylase (DDC), and L-3-phosphoserine phosphatase (L3PP). RESULTS: Out of the 12 human gastric cancer cell lines we tested, CEA was overexpressed in four cell lines (33%), CK20 in one (8%), DDC in six (50%) and L3PP was expessed in all the lines (100%). Out of the 10 gastric cancer tissues we tested, CEA was overexpressed in nine tissues, CK20 in eight, DDC in nine and L3PP was overexpressed in all the tissues. L3PP was overexpressed in all the gastric cancer cell lines and tissues, but the levels of overexpression were lower than those of CEA and DDC. CONCLUSION: Multiple genetic marker analysis can compensate for the weak points of single marker analysis when testing gastric cancer, and three mRNAs of CEA, DDC and L3PP can be used as candidate genes.
Carcinoembryonic Antigen ; Cell Line ; Dopa Decarboxylase ; Genetic Markers* ; Humans ; Keratin-20 ; RNA, Messenger ; Stomach Neoplasms*

Thymic carcinomas are uncommon malignant tumors, and thymic adenocarcinomas are extremely rare. Here, we describe a case of primary thymic adenocarcinoma in a 59-year-old woman. Histological examination of the tumor revealed tubular morphology with expression of cytokeratin 20 and caudal-type homeobox 2 according to immunohistochemistry, suggesting enteric features. Extensive clinical and radiological studies excluded the possibility of an extrathymic primary tumor. A review of the literature revealed only two global cases of primary tubular adenocarcinomas of the thymus with enteric immunophenotype.
Adenocarcinoma* ; Female ; Genes, Homeobox ; Humans ; Immunohistochemistry ; Keratin-20 ; Middle Aged ; Thymoma ; Thymus Gland*

Merkel cell carcinoma is a rare, aggressive skin cancer that occurs most frequently in the elderly on sun-exposed areas. However, any possible cutaneous or mucosal sites may also be involved. It usually presents as a rapidly- growing, painless, single red or purple colored cutaneous papule, nodule or indurated plaque that may elude diagnosis until histopathologic examination. We report a case of an 83-year old female patient who presented with a 3 x 3.5 cm sized, skin-colored, painful nodule on the left mandibular angle area. A new red nodule had combined on the original lesion after 6 months, and showed unusual clinical manifestation. Microscopically, the tumor cells were uniform with round to oval-shaped nuclei and scanty cytoplasm, and they showed a trabecular arrangement. In immunohistochemical studies, the patient was reactive to cytokeratin-20, and focally reactive to NSE and synaptophysin.
Aged ; Aged, 80 and over ; Carcinoma, Merkel Cell* ; Cytoplasm ; Diagnosis ; Female ; Humans ; Keratin-20 ; Skin Neoplasms ; Synaptophysin

PURPOSE: Axillary lymph node metastases are the single most important predictor of overall survival in patients with breast cancer. Micrometastases are defined by the American Joint Committee on Cancer as tumor foci less than or equal to 2 mm in greatest dimension. Recently, up to 30% of breast cancer patients were reported to have micrometastases. In this paper, to assess the rate of micrometastases in patients with stage I breast cancer, we attempted to determine the most useful marker of the micrometastases in node negative cases by routine histopathologic examination of regional lymph nodes and comparison of the results with the influencing factors on prognosis. MATERIALS AND METHODS: We performed immunohisto chemical staining for pancytokeratin, cytokeratin 7, cytokeratin 20 and CEA to identify which protein was the most useful marker for the detection of micrometastases in 86 node negative cases and determined the correlation between histological and clinical data. RESULTS: A total of 5 lymph nodes in 5 separate cases showed micrometastases among the total 1,296 lymph nodes and 86 cases. The rates of micrometastases of lymph nodes and cases were 0.38% and 5.8%, respectively. The tumor type of micrometastasis was infiltrating ductal carcinoma in all cases. None of the microme tastases cases showed any relationship with tumor grade, tumor size, expression of ER and PR, patient survival rate or recurrence rate. The most useful marker to detect micrometastases was pancytokeratin. CONCLUSION: The results of this study indicate that micrometastasis of axillary lymph nodes does not carry any independent prognostic significance.
Breast Neoplasms* ; Breast* ; Carcinoma, Ductal ; Humans ; Immunohistochemistry ; Joints ; Keratin-20 ; Keratin-7 ; Keratins* ; Lymph Nodes ; Neoplasm Metastasis ; Neoplasm Micrometastasis* ; Prognosis ; Recurrence ; Survival Rate

Fibrolamellar carcinoma (FLC) is a rare variant of hepatocellular carcinoma (HCC). A 26-year-old female presented a hepatic mass and mild elevation of liver enzymes. Viral markers were negative, and levels of tumor markers were normal. Radiologically, the mass was well demarcated with central dot-like calcification and hypervascularity. Under the diagnosis of hepatocellular carcinoma, right lobectomy was performed. The tumor was grayish yellow with central fibrosis and focal hemorrhage and invaded a septal bile duct. Non-neoplastic liver was unremarkable. Microscopically, the tumor consisted of large polygonal cells in sheets, cords, and pseudoglands that were interwound by dense collagenous stroma. Tumor cells had abundant deeply eosinophilic cytoplasm and large nuclei with prominent nucleoli. Intracellular bile pigments and pale bodies were present. Tumor cells were diffusely immunostained for cytokeratin 7 (CK7), but not for cytokeratin 20 (CK20). Strong expression of CK7 in the present case suggests dual differentiation of FLC.
Adult ; Bile Ducts ; Bile Pigments ; Biomarkers ; Carcinoma, Hepatocellular* ; Collagen ; Cytoplasm ; Diagnosis ; Eosinophils ; Female ; Fibrosis ; Hemorrhage ; Humans ; Keratin-20 ; Keratin-7* ; Keratins* ; Liver ; Biomarkers, Tumor