Perivascular epithelioid cell tumors are soft tissue tumors that can occur in various locations in the body whose incidence is rising. Hepatic PEComas are quite rare and diagnosis involves positivity of Melan-A and HMB45 on immunohistochemistry. Usual treatment is surgery for benign tumors and chemotherapy including mTOR inhibitors for malignant tumors. Here we discuss the radiological and path...

Background. Melanomas of the urinary bladder and urethra are rare. Aims. To review the literature on the disease. Methods. Various Internet databases were used to identify reported cases of the disease. Results. Less than 30 cases of primary melanoma of the urinary bladder and urethra have been reported in the literature and they have been associated with melanosis and commonly with metastases....

Benign melanotic lesions of the vagina are uncommon and only a few cases have been reported in the literature. A 34-year-old woman was referred because of a Vaginal Intraepithelial Neoplasia 1 biopsy result. On the gynecological examination, two different hyperpigmented areas were noted in the vagina. The colposcopic visualization of the cervix and vagina found an aceto-white lesion at the righ...

A perivascular epithelioid cell tumor (PEComa) is a peculiar growth defined as a mesenchymal tumor composed of histologically and immunohistochemically distinct perivascular epithelioid cells (PECs). Because neither normal counterparts nor precursor lesions of PEComa have been identified, we examined minute PEC nests, ranged from 0.8 mm to 10 mm, to investigate the possible origin of the PEComa...

Renal inflammatory pseudotumor is uncommon, benign tumor that has been classified into separate group but there is a risk that this lesion could be misdiagnosed. The aim of this work is to report a new case of 57-years-old man presented in our hospital with hematuria, minimal grade fever and right flank pain. Magnetic resonance imaging (MRI) and sonography revealed a tumor of the right medioren...

Reelin is an extracellular signaling protein synthesized by Cajal-Retius cells in utero and early after birth, its presence being signaled in adult life too. Reelin acts on its receptors, VLDLR and ApoER2, acting on cytoskeleton, controlling migration and subsequently positioning and stabilizing the cortical neurons. We investigated the reelin presence and its receptors, VLDLR and ApoER2, in me...

Cutaneous melanoma (M) can develop through two progression phases: the radial growth phase of M (RGPM) and the vertical one. This distinction has a practical relevance in defining lesions with potential for a metastatic course. We analyzed the morphological attributes (intraepidermal proliferation type, inflammatory infiltrate, mitogenicity, Breslow thickness, Clark level, ulceration) and the i...

Recent studies have demonstrated that cathepsin K seems to be a powerful marker in identifying the microphthalmia associated transcription factor (MITF) family tumors such as renal perivascular epithelioid cell neoplasms (PEComas), alveolar soft part sarcoma, and translocation-associated renal cell carcinomas. However, the expression of cathepsin K in melanocytic lesions has not been well chara...

BACKGROUND Although Merkel cell carcinoma (MCC) exhibits specific clinical and histologic features, differentiation from other cutaneous neoplasms, such as lymphoma, metastatic oat cell carcinoma and malignant melanoma (MM), may sometimes be difficult. OBJECTIVE The aim of our study was to immunohistochemically differentiate MCC from MM. METHODS Paraffin sections from 6 cases of primary MCC...

Perivascular epithelioid cell tumors (PEComas) are a group of rare mesenchymal neoplasms. Gastrointestinal PEComas are exceptionally rare, there being only a few case reports in the literature involving the colon and small intestine. Nearly all PEComas show immunoreactivity for both melanocytic (HMB45 and/or Melan-A) and smooth muscle (actin and/or desmin) markers. A 36-year-old male was admitt...