We report on a 60-year-old woman with neuroendocrine carcinoma of the left breast metastasizing to renal cell carcinoma (RCC) of the left kidney and to adrenal gland. A yellow, well-circumscribed tumor, 11 cm in largest diameter and limited to the kidney, was found. Histopathology revealed RCC with foci of neuroendocrine differentiation. Solid sheets of hyperchromatic epithelioid cells with hig...

Clear cell tumor of the lung (CCTL) is an extremely rare neoplasm with about 50 cases reported in the literature so far. CCTL belongs to a family arising from putative perivascular epithelioid cells and is otherwise named as "sugar tumor" due to its high cellular glycogen concentration. Due to its rarity, diagnostic features of this entity are not widely known and this usually leads to misdiagn...

Melanocytes sustain a lifelong proliferative potential, but a stem cell reservoir in glabrous skin has not yet been found. Here, we show that multipotent dermal stem cells isolated from human foreskins lacking hair follicles are able to home to the epidermis to differentiate into melanocytes. These dermal stem cells, grown as three-dimensional spheres, displayed a capacity for self-renewal and ...

Primary malignant melanoma of the esophagus (PMME) is a malignant tumor which occurs in the melanin cells of esophageal mucosal epithelial basal layer. PMME is a rare disease with an extremely poor prognosis. PMME represents only 0.1% to 0.2% of all esophageal malignant tumors. Dysphagia, retrosternal or epigastric discomfort or pain is the most frequent symptom at presentation. Retrosternal, e...

Primary malignant melanoma of uterine cervix is a rare and aggressive neoplasm. Approximately 3%-7%of malignant melanomas in women develop within genital tract. Majority occurs in vulva or vagina, but cervix is a rare site. Age range for cervical melanoma is from 19 to 83 years with peak incidence between 60 to 70years. Malignant melanoma presents with vaginal bleeding or discharge and appears ...

Epithelioid angiosarcoma of the parotid gland is rare, and may pose a great diagnostic challenge. We report a case of primary epithelioid angiosarcoma in a 64-year-old male without history of radiation. The histopathological findings demonstrated a high grade epithelioid neoplasm. Immunostaining showed that the tumor was positive for the pan-cytokeratin, p63, cytokeratin18, Vimentin and vascula...

Perivascular epithelioid cell tumors (PEComas) are a rare type of mesenchymal neoplasms characterized by a proliferation of perivascular cells with an epithelioid phenotype and expression of myo-melanocytic markers. The majority of PEComas seem to be benign and usually their prognosis is good. Malignant cases are extremely rare, exhibiting a malignant course with local recurrences and distant m...

INTRODUCTION We present the immunohistochemical (IHC) analyses of a series of four kidney tumors currently classified as mucinous tubular and spindle renal cell carcinoma (WHO), a tumor with uncertain histogenesis and differentiation. Our aims were to determine an immunoprofile and to add clinical and morphological information about this rare renal carcinoma. MATERIAL AND METHODS The four tum...

BACKGROUND We present a case of perivascular epithelioid cell tumor (PEComa), which clinically and histologically mimics a gastrointestinal stromal tumor (GIST). CASE PRESENTATION A 42-year-old woman was found to have a mass in the left flank during her annual medical checkup. Computed tomography examination revealed a submucosal tumor of the descending colon. Surgeons and radiologists suspec...

BACKGROUND Familial progressive hyper- and hypopigmentation (FPHH) is a rare genodermatosis that is characterized by diffuse hyper- and hypopigmented spots on the skin and mucous membranes. It is caused by a pathogenic mutation of the KITLG gene. OBJECTIVES To investigate the clinical features and mutation of the KITLG gene in a Chinese family with FPHH. METHODS Histopathological and immuno...