1/59. Pseudomesotheliomatous carcinoma involving pleura and peritoneum: A clinicopathologic and immunohistochemical study of three cases.Pseudomesotheliomatous carcinoma is a rare variant of peripheral adenocarcinoma of the lung that can manifest clinical, radiologic, and pathologic features similar to malignant mesothelioma. We present three patients with pseudomesotheliomatous carcinoma of the lung. In one patient the carcinoma extended beyond the thorax and extensively involved the peritoneum, mesentery, omentum, and intestines. All patients experienced weight loss and chest pain. All were white men aged 63, 65, and 67 years. Two were smokers and had shortness of breath, cough, and pleural effusion. One had a history of asbestos exposure. No patient developed dyspnea or hemoptysis. One was successfully treated for prostatic carcinoma 18 months earlier. Radiographically, all tumors were pleura-based. Grossly, the tumors spread extensively over pleural (and in one case peritoneal) surfaces and mimicked malignant mesothelioma. Histologically, all tumors were poorly differentiated and necrotic; two tumors exhibited spindle-cell components and desmoplasia. Mucin production was detectable in none, 10%, and 50% of tumor cells. The percentages of tumor cells immunoreactive for Ber-EP4 were 70%, 100%, and 80%; for Leu MI 0%, 90%, and 50%; for epithelial membrane antigen 80%, 80%, and 100%; for B 72.3%, 0%, 90%, and 20%; for polyclonal carcinoembryonic antigen 0%, 10%, and 10%; and for monoclonal 5%, 0%, and 0%. Of these, Ber-EP4 and B 72.3 rendered the most reliable diagnostic results. The clinical, radiologic, and gross and routine histologic findings were similar to those of a malignant mesothelioma; the final diagnosis could be made based mainly on immunocytochemical results. We have reviewed the English and German literature regarding 65 such tumors and present our experience with three additional cases. We emphasize the application of immunocytochemical studies on pleura-based poorly or undifferentiated malignant tumors of unknown origin.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
2/59. Retroperitoneal peripheral hemangioblastoma: a case report and review of the literature.central nervous system hemangioblastomas are uncommon tumors of controversial etiology that are usually found in the posterior fossa of the cranial cavity, retina, and spinal cord. Peripheral involvement is rare; only isolated case reports have been identified. We report an unusual case of hemangioblastoma involving the retroperitoneum. A 47-year-old African-American man presented with polycythemia on routine laboratory testing. Computed tomography revealed a large retroperitoneal mass near the pancreas, in a left suprarenal location, without adrenal involvement and without attachment to a nerve. Although hemangioblastoma may be associated with the von Hippel-Lindau syndrome, this patient did not have any of the stigmata of this disease. The histologic features included a highly vascular tumor with cellular areas composed of plump, pleomorphic spindled and epithelioid (stromal) cells with variable cytoplasmic lipid vacuoles and hypocellular areas with inflammatory cells and collagenous fibrils. Immunohistochemical staining showed that the tumor (stromal) cells were positive for vimentin, calponin, S-100 protein, neuron-specific enolase, and CD57 and negative for glial fibrillary acidic protein, cytokeratins, epithelial membrane antigen, CD34, HMB-45, desmin, and the actins. These morphologic and immunohistochemical findings are consistent with hemangioblastoma. To our knowledge this is the first reported case of a hemangioblastoma in this location. Based on this case we conclude that hemangioblastoma may occur in the retroperitoneum and outside of the central nervous system in a patient without von Hippel-Lindau syndrome. The immunoprofile of this case suggests that hemangioblastomas are mesenchymal neoplasms exhibiting both neural and myofibroblastic differentiation.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
3/59. Biphasic intra-abdominal desmoplastic small cell tumor in a patient with proximal spinal muscular atrophy.A case is reported of intra-abdominal desmoplastic small cell tumor (IDSCT) with biphasic histologic features in a patient with proximal spinal muscular atrophy. The tumor was composed of small epithelial cell nests with spindle cell sarcomatous areas. Both areas were surrounded by a desmoplastic stroma. Immunohistochemical studies revealed reactivity for low molecular weight cytokeratin, epithelial membrane antigen, vimentin, desmin and Leu-7 in both areas. Electron microscopic examination demonstrated paranuclear aggregates of intermediate filaments, zonula adherens and basement membrane-like material in the epithelial cells, while spindle cells in the tumor had fewer intracytoplasmic organelles. However, intermediate or transitional forms of both types of tumor cells were frequently observed. Although IDSCT are known to express multi-phenotypes immunohistochemically, attention should be paid to the broad spectrum of cell morphology in these tumors.- - - - - - - - - - ranking = 2keywords = membrane (Clic here for more details about this article) |
4/59. leiomyoma of the extraperitoneal round ligament: CT demonstration.We report the computed tomography (CT) description of a leiomyoma involving the extraperitional portion of the round ligament. Although unusual, such a lesion may mimic other mass lesions in this vicinity including adenopathy, endometriomas, and inguinal hernias.- - - - - - - - - - ranking = 567.5558805635keywords = ligament (Clic here for more details about this article) |
5/59. US and CT diagnosis of a twisted lipomatous appendage of the falciform ligament.Pathologic conditions of the falciform ligament leading to surgical intervention are extremely uncommon. We report a case of twisted lipomatous appendage of this ligament, demonstrated by US and CT. To our knowledge, there have been no previous reports of this entity. The extraperitoneal nature of the lesion was found by realtime sonography, but CT only was able to characterize its lipomatous nature and relationship with the falciform ligament. This lesion should be considered in the differential diagnosis of intra-abdominal focal fat infarction (IFFI), a recent vocable essentially regrouping infarction of omentum and epiploic appendages.- - - - - - - - - - ranking = 794.5782327889keywords = ligament (Clic here for more details about this article) |
6/59. HHV8-negative primary effusion lymphoma of the peritoneal cavity presenting with a distinct immunohistochemical phenotype.Primary effusion lymphoma (PEL) has been recognized as a body-cavity-based lymphoma that was originally reported to be associated with human herpes virus 8 (HHV8) infection, and was frequently found in human immunodeficiency virus-positive (hiv) patients. Here we describe an autopsy case of PEL of the peritoneal cavity in an immunocompetent patient. Cytological analysis of tumor cells within ascites revealed immunocytochemical features of keratin positivity and CD45 negativity. At autopsy, the presence of a massive volume of ascites as well as diffuse tumor cell infiltrates within the serosa of the intestine and mesenterium were observed. Tumor cells were morphologically similar to anaplastic large-cell lymphoma, but were immunohistochemically positive for keratin and epithelial membrane antigen (EMA). They also showed no reactivity to representative lymphocyte surface markers including CD45, in addition to being negative for CD30 and p80NPM/ALK. Molecular analysis of the tumor cells revealed monoclonality of the immunoglobulin heavy-chain gene rearrangement which demonstrated a lymphoma of the B-cell lineage. Furthermore, HHV8 was not detected by immunohistochemical analysis, PCR or nested PCR technique. Based on these results, we consider the present case to be an HHV8-negative PEL with keratin and EMA positivity.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
7/59. Replacement of the uterus by malignant mesothelioma of the peritoneum: a case report.Malignant mesothelioma of the peritoneum is a rare tumor that must be distinguished from the more common primary peritoneal serous epithelial neoplasms. We report a case of a 66-year-old female presenting with weight loss, anemia, and a large pelvic mass on ultrasound. At laparotomy a large (9 x 6.5 x 3.5 cm) mass in the anatomical position of the uterus was found in the minor pelvis. The uterus, tubes and ovaries could not be identified. Palpable paraaortic lymph nodes and liver nodules were found. Immunohistochemically the tumor cells were positive for cytokeratin, epithelial membrane antigen and vimentin-CEA, but S-100 protein and Leu-M1 were negative. Remnants of the uterine corpus, fallopian tubes and ovaries could not be identified. The overall features were best regarded as malignant peritoneal mesothelioma. There have been reports of mesotheliomas involving the uterus. However, this is the first reported case of mesothelioma causing total replacement of the uterus.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
8/59. Pseudopapillary solid cystic tumor arising from an extrapancreatic site.A case of pseudopapillary solid cystic tumor arising in the omentum of a 46-year-old woman is presented. A well-defined, encapsulated tumor measuring 5.2 x 4.0 x 4.0 cm was histologically characterized by a combination of solid and pseudopapillary growth patterns of tumor cells with abundant pale-to-eosinophilic cytoplasm. No pancreatic tissue was observed within or adjacent to the tumor. Immunohistochemically, the tumor was positive for vimentin, epithelial membrane antigen, and alpha1-antichymotrypsin. Ultrastructurally, the tumor cells contained electron dense granules of variable sizes, most likely representing lysosomes. flow cytometry showed a diploid dna content with a high S-phase fraction. The patient was well without recurrence 3 months after diagnosis. It is important to include pseudopapillary solid cystic tumor in the differential diagnosis of omental tumors.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
9/59. Peritoneal endometriosis in the broad ligament presenting as a large tumor.Peritoneal endometriosis presenting as a tumor is very rare. A case of peritoneal endometriosis in the broad ligament presenting as a large tumor is reported. A 39-year-old woman had a solid and cystic tumor with many microcysts, measuring 17 x 13 x 3.5 cm, mainly located in the right posterior broad ligament. Histologically, the tumor consisted of many endometrial glands associated with various amounts of endometrial stroma. Neither the glands nor the stromal cells had cellular atypia. We diagnosed peritoneal endometriosis presenting as a tumor. Among the six cases (five previously reported cases and our case) of tumor-like endometriosis in the peritoneum, two cases (33%) had received tamoxifen therapy and four cases (67%) had cystic or solid and cystic tumor. Among them, the tumor size ranged from 3 to 17 cm in diameter, and our case was the largest. In conclusion, this case is rare, but it is important for pathologists to be aware of the phenomenon (that extensive peritoneal endometriosis produces a large tumor) in the histological diagnosis of a tumor in the peritoneum.- - - - - - - - - - ranking = 681.0670566762keywords = ligament (Clic here for more details about this article) |
10/59. Late recurrence of malignant melanoma presenting as peritoneal "carcinomatosis".Malignant melanoma is a relatively rare malignancy that arises from melanocytes and accounts for approximately 1% of all malignancies reported in the united states. Malignant melanoma can develop in any part of the skin or mucosal membranes. It metastasizes to all organs of the body and often demonstrates unpredictable metastatic behavior. Late recurrence of malignant melanoma, defined as occurring 10 or more years after diagnosis and treatment, is a rare but characteristic metastatic behavior of malignant melanoma. We present a case of a late recurrence of malignant melanoma presenting with diffuse peritoneal studding.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
| | Next -> |