Autochthonous borderline tuberculoid leprosy in a man from Florida.

Leprosy (Hansen's disease) is a chronic contagious granulomatous disease principally affecting the skin and peripheral nervous system, caused by Mycobacterium leprae. In this report, we present a case of autochthonous leprosy in a man from Florida as the first human case reported from this region. Authors believe dermatologists need to be aware of the possibility of autochthonous transmission of leprosy in the Eastern-Southern United States, and should consider leprosy in any patient with atypical skin lesions, even when a history of contact with armadillo is missing.

Matrical Carcinoma With Melanocytic Proliferation and Prominent Squamoid Whorls.

Matrical carcinoma (pilomatrix carcinoma) is a rare follicular low-grade malignancy with matrical differentiation. A pigmented variant with admixed dendritic melanocytes is exceedingly rare with only 7 cases reported in the literature. The diagnosis of malignancy can be difficult to establish. The authors report a case of a 79-year-old woman with a matrical carcinoma who presented with an ulcerated nodule on the posterior right leg, measuring 2.2 cm in greatest dimension. The excisional biopsy showed irregularly shaped dermal and subcutaneous nodules ranging in size from 0.1 to 0.5 cm. The nodules were composed of aggregates of large atypical basaloid cells, with multiple, sometimes atypical, mitoses, admixed with ghost cells, and central necrosis en masse. In addition, the neoplasm was characterized by focal marked melanocytic proliferation and multiple whorls of pink eosinophilic material reminiscent of keratin pearls (squamoid whorls). The basaloid cells were positive for beta-catenin both in the nuclei and the cytoplasm and negative for BerEp4. S100, Melan-A, and HMB45 highlighted the melanocytic dendritic cells. Pan-cytokeratin was negative in the ghost cells and focally positive in the squamoid whorls. Squamoid whorls seem to be a significant feature of matrical carcinoma.