Primary malignant deciduoid peritoneal mesothelioma: a report of the cytohistological and immunohistochemical appearances

Primary Malignant Deciduoid Mesothelioma: A Challenging Diagnosis

Primary malignant deciduoid mesothelioma is a rare subtype of epithelioid mesothelioma that was first described in the peritoneum in young women without a history of asbestos exposure. It was thought to be a distinct clinicopathologic entity with ominous prognosis; recent studies have better characterized this entity. On morphology, primary malignant deciduoid mesothelioma is characterized by cytomorphologic features resembling decidualized tissue. Pleomorphism is variable. The immunoprofile is similar to other epithelioid mesotheliomas. The prognosis is the same as other epithelioid mesotheliomas and seems to depend on histological grade.

Malignant Deciduoid Mesothelioma: case presentation of an exceptional variant and review of the literature

BACKGROUND

Malignant Deciduoid Mesothelioma (MDM) is an extremely rare variant of epithelioid mesothelioma. It was first described in young females, in the peritoneum, and its relation with asbestos was not well defined. Later reports, have shown that this variant may also occur in the pleura, the pericardium and the tunica vaginalis of elderly people, who had been exposed to asbestos.

CASE PRESENTATION

We report a case of malignant deciduoid mesothelioma that occurred in the peritoneal cavity, and the omentum of a 35-year-old woman. The patient had never been exposed to asbestos.

CONCLUSIONS

Through this observation, we describe clinical, histopathological, and immunohistochemical findings of deciduoid mesothelioma, and review the literature reports.

Decidualization of Endometriosis in Macaques

The decidua is the superficial portion of endometrium that transforms, or decidualizes, under the influence of progesterone to nourish the early embryo during pregnancy. Deciduae outside the uterus are found in nearly 100% of human pregnancies. This condition, known as deciduosis, may mimic malignancy, resulting in additional diagnostic procedures that place the mother, baby, or both at risk. Deciduosis has been described in both Old World and New World nonhuman primates in conjunction with pregnancy and after treatment with exogenous progestins. Here the authors present 6 cases of deciduosis associated with endometriotic lesions in female rhesus and cynomolgus macaques (Macaca mulatta and Macaca fascicularis). Full diagnostic necropsies with histologic analyses were performed on all animals. Deciduae were stained with hematoxylin and eosin and by immunohistochemistry for vimentin, CD10, progesterone receptor, estrogen receptor, desmin, cytokeratin, kermix P8, chorionic gonadotropin, human placental lactogen, and calretinin. The most common clinical signs were abdominal pain (4 of 6) and anorexia (2 of 6). At necropsy, macaque uteri were often enlarged or disfigured (4 of 6) with abundant fibrous adhesions (5 of 6). Affected tissue consisted of epithelial-lined cysts and decidualized stroma with scattered gamma/delta T cells. Decidualized stromal cells were large and polyhedral with abundant cytoplasm and round vesicular nuclei. They stained positive for vimentin, CD10, progesterone, and estrogen. In summary, these cases illustrate deciduosis in 6 nonhuman primates with endometriosis. Understanding decidualization in nonhuman primates will aid in elucidating the pathophysiology of deciduosis during pregnancy or endometriosis and potentially lead to new interventions.

Fine needle aspiration biopsy of metastatic malignant mesothelioma with myxoid change and signet ring cells: A case report and review of the literature

Malignant mesothelioma (MM) is a rare neoplasm, which is most commonly encountered in cytology through effusion specimens. Fine needle aspiration biopsy of MM, particularly the epithelioid subtype, can be a source of diagnostic difficulty and may mimic sampling of an adenocarcinoma. This is the first case report to demonstrate abundant extracellular myxoid material and numerous intracellular vacuoles, including signet ring cells, in a fine needle aspirate of metastatic MM. A review of the literature for myxoid change and vacuoles in fine needle aspiration biopsies of MM discloses that vacuoles are found in up to 35% of aspirates of MM, but myxoid change is very rare, reported in <5% of the cases. Cytologists should be aware of this rare morphologic pattern of metastatic epithelioid MM.

Deciduoid mesothelioma: report of 21 cases with review of the literature

Deciduoid mesothelioma is a rare variant of epithelioid mesothelioma that was initially considered to occur exclusively in the peritoneum of young women who had no history of asbestos exposure and to be characterized by an aggressive clinical course, but it was later demonstrated that this tumor could also occur in the pleura of older men and women who had been exposed to asbestos. Some subsequent studies have also indicated that the clinical course is no different from that of conventional epithelioid mesothelioma. Herein are reported 21 cases of deciduoid mesothelioma that were investigated using a large panel of immunohistochemical markers, 9 of which were also studied by electron microscopy. Fifteen of the patients were male and 6 were female (mean age, 60 years). Seventeen of the cases originated in the pleura and four in the peritoneum. Histologically, all of the cases were composed of large, polygonal or ovoid cells with well-defined cell borders, dense eosinophilic cytoplasm, and single or multiple nuclei. In some cases, the cells exhibited a wide variation in their size and shape, frequent loss of cell cohesion, marked nuclear atypia, and high mitotic activity (>5 per 10 HPF); whereas, in others, the cells were more cohesive, less pleomorphic, and the mitotic activity low. As the survival of patients in the first group of cases was shorter (mean, 7 months), when compared with that of the latter (mean, 23 months), it is concluded that the differences in prognosis reported in deciduoid mesothelioma are due to the existence of a high-grade subgroup that presents highly aggressive clinical behavior. Therefore, when a high-grade deciduoid mesothelioma is present, it should be reported as it can significantly affect prognosis and treatment. The use of immunohistochemistry and electron microscopy in assisting in the differential diagnosis of deciduoid mesothelioma is also discussed.

Deciduoid pleural mesothelioma--a rare entity in a young woman

Deciduoid Mesothelioma is a rare variant of epithelioid mesothelioma; it was initially thought that it only occurred in the peritoneum of young women and had nothing to do with asbestos exposure. However, since these early findings it has also been observed in the pleura and the pericardium, with possible association to asbestos. In general the prognosis is poor compared to epithelioid mesothelioma. 45 cases have been reported in the literature up to now, 22 of these were located in the pleural cavity. The authors describe a case of deciduoid pleural mesothelioma in a 40-year-old-woman who presented with right pleuritic chest pain, with no history of asbestos exposure, treated with chemotherapy followed by surgery and who died postoperatively.