'Monster cell' melanoma with pulmonary metastasis and cyclin D1 amplification.

Markedly pleomorphic epithelioid cells with high mitotic activity, giant cell formation, very large atypical nuclei, multiple nucleoli and abundant cytoplasm characterize 'monster' cells and may indicate aggressive tumor behavior. Very rare reports of melanomas comprised of 'monster cells' or cells with comparable histomorphological features, found in tissue samples from skin, lymph nodes, CNS, oral cavity and ileum have been published in the literature. This case is the first such description in the lung, and it is characterized with a battery of immunohistochemical stains; BRAF mutation status was negative, and fluorescence in situ hybridization analysis revealed increased copy number gains in 11q (cyclin D1), which is associated with poor prognosis in melanoma.

Combined melanocytic nevi: histologic variants and melanoma mimics.

Combined melanocytic nevi are composed of 2 or more distinct populations of nevomelanocytes. Most commonly used to describe the combination of blue nevi with common nevi, it may also be applied to other combinations of benign melanocytic proliferations, including Spitz nevi and nevi with deep dermal pigmented nevomelanocytes. We report the incidence and distribution of these tumors at the Massachusetts General Hospital over the past decade and review guidelines for diagnostic criteria and nomenclature.

Patient with amyloidoma of the ulnar nerve and salivary glands.

Amyloidomas of the peripheral nervous system have been reported rarely. We describe a patient with a history of localized amyloidosis of the salivary glands who presented a few years later with paresthesias of her left medial arm, forearm, and fifth digit. A mass affecting the left ulnar nerve was confirmed by MRI studies.

Apocrine mixed tumor of the skin with a prominent pilomatricomal component.

Pilomatrical differentiation within an apocrine mixed tumor (AMT) when present is only focal and has not been reported to be extensive. We herein report an AMT with prominent pilomatrical differentiation. A 47-year-old male presented with a 0.

Atypical thymoma: a report of seven patients.

Background: Most thymic neoplasms fall under the designation of thymoma, consisting of well-differentiated epithelial cells, resembling normal thymus. At the opposite spectrum are thymic carcinomas; the cell of origin while similar is malignant. Recently a third category of thymic neoplasms, atypical thymomas, has been recognized representing thymic neoplasms manifesting atypia although without overt cytomorphologic criteria of malignancy.