Perineurioma of the colon: an uncommon tumor with an unusual location. Report of a case and review of the literature.

Perineurioma is a relatively rare benign peripheral nerve sheath tumor composed of cells resembling to normal perineurium. Although this tumor may arise in the context of a nerve (intraneural perineurioma), extraneural perineurioma does occur, frequently involving the soft tissues of the lower and upper extremities, trunk and head and neck. Rarely it has also been reported in visceral organs, including gastrointestinal tract. We herein describe the clinicopathologic features of a rare case of a perineurioma presenting as a polypoid lesion of the sigmoid colon, emphasizing the pathologic diagnostic clues.

Molecular and immunohistochemical profile of a basaloid (cloacogenic) carcinoma of the sigmoid colon: possible predictive value for clinical outcomes.

A 61-year-old woman was hospitalized with a 5-week history of abdominal discomfort, change in bowel habits, and weight loss. Colonoscopy showed a protruded tumor of the sigmoid colon first diagnosed as undifferentiated carcinoma. Surgical resection of the sigmoid colon was performed. Histological examination of the surgical specimen showed a proliferation of basaloid cells arranged in tumor clusters with central comedonecrosis and peripheral palisading of the nuclei. The tumor invaded the subserosa and presented liver metastasis without lymph node metastases. The tumor cells were marked by keratin AE1/AE3, keratin 5/6, epithelial membrane antigen, bcl-2, vascular endothelial growth factor, CD105, neuron-specific enolase, MLH-1, MSH-2, and p53, and were negative for keratin 7/20, chromogranin, synaptophysin, carcinoembryonic antigen, p63, c-KIT, and maspin. A high p53 nuclear index was also detected. On the basis of these characteristics and molecular examinations, the final diagnosis was microsatellite stable/human papilloma virus-negative/K-ras mutated/BRAF wild-type basaloid carcinoma (BC). Only seven BCs of the colon were reported in the literature, this being the eighth one and the first case that reports new molecular findings about microsatellite instability, K-ras/BRAF mutations, angiogenesis, and maspin expression in BC, with direct involvement in targeted therapy.

Primary invasive micropapillary carcinoma of the colon: case report and review of the literature.

Invasive micropapillary carcinoma is associated with frequent lymph node metastases and adverse clinical outcome. It has been reported in breast, urinary bladder, lung and the parotid gland, but very rarely in the colon. We report a new case in a 63-year-old man involving the colon, and discuss the clinicopathologic features of this rare and particularly aggressive tumour.

Histomorphometric characteristics and cellular kinetics of colorectal polyps with epithelial serrated proliferation adjacent to carcinoma.

Four cases of colorectal polyps with epithelial serrated proliferation (CP-ESP) with malignant transformation were studied. In CP-ESP adjacent to carcinoma, if the nuclear size in the surface layer was significantly smaller than those in the bottom and the middle layers of the crypts, the specimen was defined as zone formation positive. If there was no significant difference among the layers, the specimen was defined as zone formation negative. Cell kinetics were evaluated using Ki-67 immunostaining. The CP-ESP regions of cases 1 and 2 showed zone formation with inferior and lateral glandular branching, and were qualitatively hyperplastic on cell kinetics. Cases 3 and 4 showed inferior and lateral glandular branching with no zone formation, and were kinetically neoplastic (adenoma). The histogenesis of hyperplastic polyps with atypia (cases 1 and 2) involves the hyperplastic polyp-carcinoma sequence. In contrast, the development of tubulovillous adenoma or serrated adenoma (cases 3 and 4) may involve the tubulovillous adenoma-carcinoma or serrated adenoma-carcinoma sequence.

Assessment of biomarkers in paired primary and recurrent colorectal adenocarcinomas.

PURPOSE: Recurrent colorectal cancers respond poorly to anticancer treatment including radiotherapy. To better understand the biological characteristics of the recurrent colorectal tumor, we investigated various biomarkers regulating cell proliferation and cell loss in paired primary and recurrent colorectal tumor specimens within each individual. METHODS AND MATERIALS: From a total of 11 colorectal adenocarcinoma patients, 22 specimens of paired primary and recurrent tumors were obtained for analysis. Apoptosis was evaluated by TUNEL labeling of apoptotic DNA fragmentation. Other biomarkers including proliferating cell nuclear antigen (PCNA), p53, WAF1, p34cdc2, and cyclins B1 and D1 were analyzed by immunohistochemical stains. RESULTS: PCNA index (PCNAI) showed an increase in 6 and a decrease in 5 recurrent tumors compared to primary tumors. Median PCNAI in primary and recurrent tumors were 33.5 and 48.3, respectively (p = 0.16). In contrast, the apoptotic index (AI) decreased in 9 of 11 recurrent tumors compared to primary tumors. Median AI decreased from 4.3 in primary tumors to 1.4 in recurrent tumors (p = 0.04). The p53 expression increased in more than half of recurrent tumors compared to primary tumors. Mean staining score increased from 0.7 in primary tumors to 1.2 in recurrent tumors (p = 0.059). WAF1 and cyclin B1 did not show significant change. In contrast, both cyclin D1 and p34cdc2 increased significantly in recurrent tumors. These two biomarkers showed increased expression in 8 (cyclin D1) and 7 (p34cdc2) recurrent tumors, respectively, compared to their primary counterparts. Mean staining scores of both biomarkers in recurrent tumors increased by more than twofold compared to those in primary tumors and these differences were statistically significant (cyclin D1, p = 0.007; p34cdc2, p = 0.008). CONCLUSION: This study showed significantly decreased apoptosis in recurrent colorectal tumors compared to their primary counterparts. The underlying regulatory mechanisms included increased expression of p53 and altered cell cycle regulators such as increased cyclin D1 and p34cdc2. With further study, it may be used for developing a new therapeutic strategy for the treatment of recurrent colorectal cancer.

Adenocarcinoma arising in extragonadal endometriosis: an immunohistochemical study.

BACKGROUND: Malignant transformation is an infrequent but reported complication of endometriosis. Previous reports of these cases have been limited to clinicopathologic studies based on routine histologic examination of these tumors, whereas, to the authors' knowledge, characterization of these lesions based on immunophenotype and hormone receptor and oncoprotein expression has not been described. METHODS: Using commercially available monoclonal antibodies, the authors studied three recent cases of adenocarcinoma arising in extragonadal endometriosis using paraffin immunohistochemistry. Proteins examined included different cytokeratin (CK) subtypes, as well as hormone receptor status, proliferation rate, and oncoprotein expression. RESULTS: All three cases presented clinically and macroscopically as colonic masses, and the tumors expressed an endometrial CK phenotype (CK7+, CK20-). In contrast, the adjacent benign colonic epithelium expressed the expected opposite phenotype (CK7-, CK20+). Estrogen receptor (ER) and progesterone receptor (PR) were expressed in one of the three tumors. Interestingly, in the ER/PR negative tumors, receptor expression was present in areas of benign endometriosis adjacent to malignancy, suggesting a loss of receptor expression with malignant transformation. The tumors also were examined for proliferation by Ki-67, and the expression of oncoproteins c-erb B-2, p53, cyclin D1, and bcl-2. All cases of malignancy had a high proliferation rate as measured by Ki-67, which was in contrast to areas of benign endometriosis which had a low proliferation rate. Of the other oncoproteins only p53 protein was detected at a significant level in all three cases. Cyclin D1 was overexpressed in two of the three cases. c-erb B2 and bcl-2 overexpression was not detected. CONCLUSIONS: The results of the current study 1) show the utility of CK subtypes in confirming endometrioid phenotype in tumors arising in extragonadal endometriosis with colonic involvement and 2) suggest that loss of hormone receptor expression and p53 oncoprotein abnormalities may be involved as mechanisms in malignant transformation in extragonadal endometriosis.

Primary Hodgkin's disease of the sigmoid colon: a case report and review of the literature.

We report the case of an 81-year-old man who underwent a segmental resection of the sigmoid colon for severe diverticular disease. Histopathologic diagnosis revealed extranodal Hodgkin's disease, and the diagnosis was confirmed by immunohistochemistry. The incidence of extranodal Hodgkin's disease is rare and represents an infrequent occurrence as a gastrointestinal neoplasm and primary gastrointestinal lymphoma. A review of the literature for gastrointestinal lymphomas with emphasis on the occurrence of Hodgkin's disease, the diagnostic features, and the site of gastrointestinal tract involvement is reported.

Immunoscintigraphy using 99mTc-labeled anti-CEA monoclonal antibody for patients with colorectal cancer.

Immunoscintigraphy by 99mTc labeled mouse CEA antibody, BW 431/26, was done for 14 patients with colorectal cancer. All patients underwent body scan 6 and 24 hours after administration of 99mTc antibody, 30 mCi/1mg. In 13 out of 14 cases (92.9%) with colorectal cancer, the specific accumulation of 99mTc was shown. The count ratio between the lesion and normal tissue indicating the accumulation of labeled antibody was calculated as 2.6 to 12.8. The hepatic metastasis could be demonstrated as cold spots in one case and as hot spots in the other case. No adverse reaction was noticed in any of patients examined. These results indicate that immunoscintigraphy by 99mTc-CEA antibody detects carcinoma of the colon excellently, and is quite useful clinically. With SPECT, it is possible to localize the site of the lesion more distinctly and to predict the accumulation of the antibody in the tumor as a treatment application.