Intraosseous malignant peripheral nerve sheath tumor with focal epithelioid differentiation of the thoracic spine.

The authors describe an extremely rare case with malignant peripheral nerve sheath tumor (MPNST) with focal epithelioid differentiation presenting as an intraosseous lesion of the spine. A 75-year-old woman presented with progressive paraplegia caused by epidural mass arising from the posterior element of the T7 vertebra. At surgery, the lesion was noted to originate from the T7 vertebra and separate from the dura and spinal nerve roots. The patient died of tumor metastases to the lungs six months after the initial presentation. Histological diagnosis was MPNST. However, the tumor also contained cystic structures lined by epithelioid cells, requiring differentiation from synovial sarcoma. From the histological and immunohistochemical features, as well as the absence of SYT-SSX fusion gene expression, the diagnosis of MPNST with focal epithelioid differentiation was made. This is the first case report of intraosseous MPNST of the spine with a peculiar biphasic appearance.

Avaliação histopatológica, imuno-histoquímica e ultraestrutural da resposta inflamatória crônica do robalo (Centropomus spp. ) ao bcg / Histopathological, immunohistochemical, and ultra-structural evaluation of chronic inflammatory response of robalo (Centropomus spp) to bcg

Objetivo do estudo foi avaliar a cinética da resposta inflamatória induzida experimentalmente com BCG em peixes modernos pertencentes ao gênero Centropomus sp. Os animais foram experimentalmente inoculados com BCG por via intramuscular na região do pedúnculo caudal sendo realizada a coleta do material nos tempos experimentais de 1, 3, 7, 14, 21 e 33 dias pós-inoculação. Afase aguda da resposta inflamatória se mostrou na forma de infiltrado composto predominantemente por células mononucleares, edemaintersticial e necrose de tecido muscular. À medida que o processo se desenvolve, observa-se a organização do foco lesional na forma de um granuloma formado por células epitelióides. Essas células, ao exame imunohistoquímico apresentaram positividade a proteína S100 e citoqueratina, indicando características macrofágicas e secretória, além de apresentarem ao exame ultra-estrutural a presença de desmossomos entre as células adjacentes. Não houve participação efetiva de células gigantes e pigmentares, sugerindo ser uma característica relacionada à espécie.

This study set out to evaluate inflammatory response kinetics afterexperimental inoculation with BCG in modern Centropomus sp. fish.BCG was applied through intramuscular injection in the caudalpeduncular region, and samples were collected for analyses at days 1,3, 7, 14, 21, and 33 post-injection. Acute phase inflammatory infiltratewas characterized by predominant mononuclear cells, intersticial edema,and muscular tissue necrosis. As the inflammatory response evolved,the lesion organized into a granuloma formed by epithelioid cells.These epithelioid cells were positive for the S100 protein and cytokeratinat histochemical analysis, which demonstrates macrophage andsecretory activity, besides ultra-structural analysis showed desmosomicjunctions within adjacent cells. It didn’t have an expressive participationof giant cells and pigment containing cells in the inflammatory reaction,suggesting that it’s a specie-specific characteristic.

Uterine perivascular epithelioid cell tumour presenting as a cervical mass

Perivascular Epithelioid Cell Tumour [PEComa] also known as myelomelanocytic tumours are uncommon, recently described mesenchymal tumours that include angiomyolipoma, clear cell "sugar" tumour of the lung, lymphangioleiomyoma and tumours composed predominantly of epithelioid cell morphology. A predilection for uterus has been described. However up till now only 14 cases of uterine PEComas have been described. All of these were seen in adult females in the peri and post menopausal age group [from 40-75years], and almost all were located in the region of body of uterus. A single case in the upper cervical region has been reported with uterine PEComatoses. We report an unusual presentation of this rare tumour presenting as a polypoidal cervical mass in a young female. Occurrence of this tumor in a young female as seen in our case warrants inclusion of PEComa in the diferential diagnosis of all epithelioid and clear cell neoplasms of uterus irrespective of age