Malignant Peripheral Nerve Sheath Tumor With Osseous Heterologous Differentiation in Uncommon Locations (Heart and Retropharynx).

We report two cases of malignant peripheral nerve sheath tumor (MPNST) in an uncommon location (heart and retropharynx) both with divergent osseous heterologous differentiation. We present the pathological and immunohistochemical studies that confirmed the neurogenic origin. The histopathology of the tumor arising in the retropharynx showed a transition from a neurofibroma to MPNST, making this a new report of an MPNST arising from a plexiform neurofibroma without neurofibromatosis.

Malignant chondroid syringoma of the face with bone invasion.

Malignant chondroid syringoma is a very rare type of malignant sweat gland tumor. Diagnosis is based on pathologic features but is complicated by the low frequency of this tumor. The authors report a new case of malignant chondroid syringoma, initially misdiagnosed as basal cell carcinoma, that exhibited very aggressive local behavior and was located on the face, a rare site for this tumor.

Salivary duct carcinoma: diagnostic clues, histology and treatment.

Salivary duct carcinoma is a very rare, highly-malignant epithelial tumour. We present a case of a 75-year-old man with a rapidly- growing salivary duct carcinoma in the parotid gland, of one month's evolution. Histopathologically, salivary duct carcinoma is characterised by its resemblance to ductal carcinoma of the breast.