Malignant melanoma can metastasize widely and vary significantly in its histological appearance; it rarely presents as a deep-seated mass without an obvious primary site elsewhere. Malignant peripheral nerve sheath tumor (MPNST) is a high-grade sarcoma characterized by conventional and epithelioid subtypes. MPNST can demonstrate heterologous differentiation, usually in the form of osteosarcomat...

Activating mutations of platelet-derived growth factor receptor α (PDGFRA) are detected in a significant proportion of gastrointestinal stromal tumors (GISTs), in addition to the more frequent mutation in c-kit. GISTs with PDGFRA mutations have been found to have several characteristic morphological features, sometimes allowing to discriminate them from GISTs with c-kit mutations. Among these, ...

Bone epithelioid angiosarcoma is rare and generally shows positive immunostaining for epithelial markers. Multicentric bone epithelioid angiosarcoma is easily misdiagnosed as carcinoma, including metastatic carcinoma, multiple myeloma, and multiple lymphoma of bone. This article describes a case of multicentric bone epithelioid angiosarcoma. The patient was first misdiagnosed as having metastat...

Sclerosing epithelioid fibrosarcoma is a rare tumour characterised histologically by a predominant population of epithelioid cells arranged in strands and nests, embedded in a fibrotic and hyalinised stroma. It is a low grade tumour with an indolent course. A 48 year old woman presented with a painful swelling over her back for six months. Investigation and biopsy revealed features of sclerosin...

Epithelioid sarcoma is a distinct sarcoma type with specific morphology and immunophenotype. An epithelioid sarcoma of the vulva is an extremely rare and aggressive tumor and most commonly occurs on the labia majora in women of reproductive age. Only few cases have been reported, especially with the presence of focal myxoid changes. Early diagnosis is difficult because of its benign appearance ...

Angiotensin II regulates vascular structure through growth and apoptosis, with implications in pathophysiology. Subtypes of vascular smooth muscle cells with specific morphology, growth, or apoptotic features have been isolated. Here, we investigated the effects of angiotensin II on apoptosis of 2 morphologically different rat aortic smooth muscle cell phenotypes. Spindle and epithelioid cell l...

Array-based comparative genomic hybridization analysis was performed on 21 malignant mesothelioma (MM) samples (16 primary cell cultures and 5 cell lines) and two reactive mesothelial hyperplasia (RM) primary cell cultures. The RM samples did not have any genomic losses or gains. In MM samples, deletions in 1p, 3p21, 4q, 9p21, 16p13 and 22q were detected frequently. We focused on 3p21 because t...

Bone epithelioid angiosarcoma (EA) is rare and characterized by large, mildly to moderately pleomorphic epithelioid cells, with abundant eosinophilic cytoplasm, vesicular nuclei, and prominent nucleoli. The tumors may arise in various locations in bone and the patients may present with unifocal or multifocal osseous disease. We present a unifocal lesion case of EA of the ilium in a 62-year-old ...

Epithelioid hemangioendothelioma is a rare vascular neoplasm which exhibits the potential for malignancy and recurrence as well as the ability to metastasize. Although numerous sites of involvement are possible, these tumors most commonly arise in soft tissues, lung, liver, bone, and lymph nodes. In this report, we describe a case of oral epithelioid hemangioendothelioma in a child. This tumor ...

Lymphoepithelioma-like carcinoma is a distinct entity among Epstein-Barr virus (EBV)-associated gastric carcinomas, characterized by the presence of a lymphoid stroma with small nests of cancer cells uniformly distributed throughout. Epithelioid granulomas with multinucleated giant cells are extremely rare in the tumor tissue. The presence of epithelioid granulomas with prominent lymphocyte inf...