Urachal Mucinous Cystadenocarcinoma.

A 57-year-old man presented with a 6-month history of pelvic fullness. He had no lower urinary tract symptoms or altered bowel habits. On examination, there was a non-tender pelvic mass which extended from the pubic symphysis to the level of the umbilicus. CT scan of the abdomen demonstrated a 22×11×11 cm cystic mass arising from the pelvis extending into the midline and superiorly to the umbilicus. Other than raised carcinoembryonic antigen of 7.6 ng/mL (<5.0), the remainder of his blood test were unremarkable. Flexible cystoscopy demonstrated a convex deformity of the bladder wall in keeping with the compression and displacement as seen on the CT. The patient underwent an open excision of the cystic structure (urachal remnant), partial cystectomy, partial excision of anterior abdominal wall and pelvic lymphadenectomy. A check cystogram performed 12 days following the initial operation was unremarkable.

Mucinous colorectal adenocarcinoma with signet-ring cells: immunohistochemical and ultrastructural study.

A primary mucinous colorectal adenocarcinoma tissue with signet-ring cells, as revealed after histological evaluation, was examined ultrastructurally. The authors also analyzed the immunohistochemical data of the tissue for serotonin, vasoactive intestinal polypeptide (VIP), bombesin, somatostatin, and glucagon, using the peroxidase anti-peroxidase (PAP) method and the immunogold labeling method for light and electron microscope, respectively. Electron microscopically mucinous adenocarcinoma was characterized by the formation of small lumen. Adenocarcinoma cells were full of mucous granules of varying electron density, providing a good environment for the tumor cells to grow. They also exhibited a significant loss of microvilli and intracytoplasmic junctions, which could allow the cells to disseminate. Signet-ring cells were located in the basal site of the ducts or in the lamina propria and appeared neoplastic, with mucin accumulation intracellularly and an eccentric crescent-shaped nucleus. The cytoplasmic organelles were decreased and at the periphery of the cell. The PAP method demonstrated that these cells were strongly positive for bombesin and also positive for vasointestinal polypeptide (VIP). The immunogold method detected bombesin immunoreactivity in the vacuoles as well as in other cytoplasmic membranes, whereas VIP was localized mainly in the plasma membrane. The location of signet-ring cells combined with the immunoreactivity for bombesin and VIP indicated that signet-ring cells were of neuroendocrine origin and probably dedifferentiated enterochromaffin-like endocrine cells. These findings have implications for understanding the biological behavior of these composite malignant tumors and could help in the knowledge of the origin of signet-ring cells.

Differential expression of laminin isoforms in ovarian epithelial carcinomas suggesting different origin and providing tools for differential diagnosis.

Immunohistochemistry was used to study the distribution of laminin (Ln) chains, collagen types IV (alpha 1/2), VII, and XVIII and Lutheran antigen (Lu) in 36 frozen ovarian carcinoma samples. Surface epithelial basement membrane (BM) of the normal ovary showed immunoreactivity for Ln alpha1, alpha3-alpha5, beta1-3, gamma1, and gamma2 chains and type IV and XVIII collagens. Chains of Ln-5 (alpha3beta3gamma2) and Ln-10 (alpha5beta1gamma1) as well as type IV and XVIII collagens were found in most tumor BMs, but Ln alpha2 chain and type VII collagen were detected only in few tumors. Contrary to serous tumors, BMs of mucinous carcinomas showed Ln alpha4 chain, but not Ln alpha1 and beta2 chains. Ln alpha1 chain was found in most endometrioid carcinomas, whereas chains of Ln-5 were only moderately detectable in comparison with serous and mucinous carcinomas. In the normal ovary, Lu immunoreactivity was confined to basal aspect in the ovarian epithelial cells, but in tumor specimens Lu immunostainings showed variable polarized and nonpolarized patterns. The results suggest that the three types of ovarian carcinoma have distinct differences in their Ln distribution and can be grouped based on their expression pattern. This suggests that they may have histogenetically different precursors and may help to distinguish these tumors from each other.

Prognostic importance of the nucleolar organizer region score in ovarian epithelial tumors.

OBJECTIVE: The score of the silver-stained nucleolar organizer region (AgNOR) is frequently found to be high in malignant tumors. We studied AgNOR in ovarian epithelial tumors diagnosed in our hospital between 1993 and 1998. MATERIALS AND METHOD: In our study 67 ovarian epithelial tumors (18 cystadenoma, 16 borderline type, 34 cystadenocarcinoma) were stained using the method previously described by Crocker. One-way ANOVA and logistic regression tests were used to find the statistical relationship between grade, recurrence, mortality rates and AgNOR scores in tumors (p values of <0.05 were considered statistically significant). RESULTS: The mean AgNOR scores of 28 mucinous and 39 serous ovary tumors were calculated. The lowest AgNOR score of 1.33 was found in cystadenomas and the highest AgNOR score of 4.92 was found in serous and mucinous cystadenocarcinomas. In addition the relationship between mortality rate, recurrence and AgNOR score in carcinomas were studied. CONCLUSION: AgNOR scores in carcinomas were found to be higher than adenomas, and the highest AgNOR score was found in grade-III carcinomas. This shows that the AgNOR score can be used as a prognostic index in malignancies.

Expression of metallothionein and nuclear size in discrimination of malignancy in mucinous ovarian tumors.

Metallothioneins (MTs) are low molecular weight proteins that control cell proliferation via their metalloregulatory function. Several studies in various tumors have shown their influence in determining response to chemotherapy and prognosis. Because there has been no such study pertaining to ovarian tumors, we investigated MT expression and nuclear size in mucinous ovarian neoplasms (12 benign, 6 borderline, and 8 malignant). The percentage of MT-positive stained cells was significantly higher in the borderline than in the benign tumors, but lower than in the malignant tumors. Single layers of cells in the borderline tumors showed mild immunostaining in 50% of the cells and moderate staining in the remaining 50%, while 83.3% of cells within multilayered epithelium showed moderate to strong immunostaining. In the carcinomas, 87.5% of tumors showed moderate to strong staining in single-layered epithelium and moderate to strong staining of all the cells in multilayered epithelium. Morphometry measurements showed that the mean nuclear area of cells in the carcinomas was significantly larger than in the borderline or benign tumors. The nuclear area of cells in the carcinomas with early recurrence or metastasis was also significantly larger than in carcinomas without recurrence or metastasis. It is concluded that MT protein expression and nuclear size are possible markers for the evaluation of the progression of malignancy in mucinous ovarian tumors.

Hepatobiliary and pancreatic mucinous cystadenocarcinomas with mesenchymal stroma: analysis of estrogen receptors/progesterone receptors and expression of tumor-associated antigens.

Hepatobiliary and pancreatic mucinous cystadenocarcinomas with mesenchymal stroma are relatively rare neoplasms that occur preponderantly in women, suggesting a role for unidentified sex-specific factor(s) in the pathogenesis of these tumors. We used paraffin tissue immunohistochemical analysis with an appropriate panel of monoclonal antibodies to look for estrogen and progesterone receptors in two cases of hepatobiliary mucinous cystadenocarcinoma with mesenchymal stroma and one case of pancreatic mucinous cystadenocarcinoma. In all three of these cases, the nuclei of tumor stroma and, in the hepatic tumors, the nuclei of tumor epithelium, reacted with both antibodies. These data strongly suggest that a relationship to hormonal functions exists for these tumors. Because of the rarity of these tumors we also investigated the expression of a variety of oncoprotein antigens, epithelial antigens, and cytoskeletal antigens. The oncoprotein antigens, p53 and c-erbB-2, were focally expressed in hepatic and pancreatic tumor epithelium; bcl-2 was focally expressed in hepatic tumor epithelium. Keratin was strongly expressed in most epithelial cells. In addition, epithelial membrane antigen, carcinoembryonic antigen, and chromogranin were focally expressed in epithelial cells. Actin and vimentin were strongly expressed in most stromal cells but not in epithelial cells, and desmin expression was similar but less widespread.

Ovarian mucinous cystadenocarcinoma with sarcoma-like mural nodules.

A rare case of ovarian mucinous cystadenocarcinoma with sarcoma-like mural nodules is reported. Macroscopically, nodular or granular lesions were scattered over the inner surface of a huge, multilocular tumor in the left ovary. The histopathological features were consistent with those of previously documented cases, except significant squamous metaplasia in the present case. The pleomorphic sarcoma-like cells showed a positive reaction for vimentin and alpha-antichymotrypsin but were negative for carcinoembryonic antigen and common epithelial membrane antigen by immunohistochemistry. Electron microscopically, the tumor cells had neither desmosomes nor secretory granules, but they possessed abundant intermediate filaments. Both immunostaining and ultrastructure suggested that the sarcoma-like nodules were derived from reactive proliferation of fibrohistiocytic cells. The fibrohistiocytic reaction seemed to occur in response to hemorrhage, because hemorrhage was reported to be associated with the mural nodules in most of the previous cases as well as ours.