An unusual epithelioid variant of perineurioma of the groin occurring in a 53-year-old man is described. The lesion appeared to be associated with a femoral nerve branch. The tumour was characterised by the presence of a syncytial proliferation of epithelioid cells, mimicking a meningioma of syncytial type. In addition there was a minor component of a conventional perineurioma. The tumour cells...

Perivascular epithelial cell tumors (PEComas), firstly described by Bonetti in 1992, are a family of mesenchymal tumor composed of perivascular epithelioid cells having epithelioid or spindle morphology and exhibiting melanocytic and myogenic immunoreactivities. We herein described a 61-year-old woman who presented with epigastric pain. Preoperative imaging studies showed that 7-cm-sized mass w...

BACKGROUND The "proximal-type" epithelioid sarcoma is a very rare kind of mesenchimal tumor characterized by the difficulty in histological diagnosis and the very aggressive biological behavior. CASE We report of a case of a 63 years old woman with a vulvar "proximal-type" epithelioid sarcoma that underwent a radical surgical staging followed by an adjuvant radiotherapy. She is on follow-up c...

Malignant renal epithelioid angiomyolipoma (EAML) is rare, and currently there is no malignant criteria for its pathological diagnosis. In the present study, the case of a patient who suffered malignant renal EAML and underwent nephrectomy is reported. The histological patterns of the tumor were composed of sheets or nests of large polygonal epithelioid cells and thick-walled blood vessels, wit...

We have performed this study to define the usefulness of an anti-human progenitor cell antigen-1(anti-CD34) to distinguish some kinds of soft tissue tumors in formalin-fixed, paraffin-embedded tissues. Sixty three cases of vascular, fibrohistiocytic, neural and other tumors were immunostained for CD34 using the streptavidin-biotin immunoperoxidase method. All of the vascular tumors including he...

BACKGROUND AND AIMS Malignant mesothelioma is an aggressive, therapy-resistant tumor. Mesothelioma cells may assume an epithelioid or a sarcomatoid phenotype, and presence of sarcomatoid cells predicts poor prognosis. In this study, we investigated differentiation of mesothelioma cells in a xenograft model, where mesothelioma cells of both phenotypes were induced to form tumors in severe combin...

Rat aortic smooth muscle cells (SMCs) cultured from intimal thickening 15 days after endothelial injury (IT-15), unlike those of normal media, show a monolayered, epithelioid phenotype and high levels of cellular retinol binding protein-1 (CRBP). Epithelioid clones obtained from the normal media suggest a "mosaicism" of arterial SMCs. Intimal cell homeostasis from the balance of proliferation a...

BACKGROUND Epithelioid sarcoma is a rare soft part tumor, the cytologic features of which have not been fully elucidated to date. We describe the cytologic features in 2 cases of primary epithelioid sarcoma with samples obtained by fine needle aspiration (FNA). CASES Case 1 was a 50-year-old male who complained of a small mass in his left palm. Case 2 was a 56-year-old female who presented wi...

Epithelioid sarcoma is a rare soft tissue sarcoma and usually resistant to chemotherapy. It has high rates of local recurrence and distant metastasis, and the prognosis after metastasis is poor. We report a case of multiple lung metastases of an epithelioid sarcoma originating in the inguinal area that we treated with the multikinase inhibitor pazopanib. The patient was a 38-year-old male who b...

Epithelioid gastrointesinal tumors (GISTs) are less likely to have c-kit gene mutations (and express CD117) than spindle cell GISTs. CD117 negative/c-kit negative GISTs can have platelet-derived growth factor alpha (PDGFRα) gene mutations, overexpress PDGFRα protein and respond to imatinib mesylate. Many cases of CD117-negative/CD117weakly positive, c-kit mutation negative and PDGFRα mutation p...