Proliferating trichilemmal tumor of the nose.

Proliferating trichilemmal tumor is a rare tumor originating in the external root sheath, that is usually found in the scalp of middle-aged or elderly females. Its histologic appearance may not correlate with its clinical behavior. In addition, there are no guidelines available for the treatment of these tumors, making its management a challenge for physicians. We report the case of a 53 year-old woman with a proliferating trichilemmal tumor on her nose, which is a very uncommon location for these lesions.

Langerhans cell histiocytosis: two clinical presentations in the same patient.

Langerhans cell histiocytosis (LCH) is a heterogeneous group of diseases characterized by a pathological proliferation of cells phenotypically similar to Langerhans cells. The disease course is variable, alternating between resolving and potentially fatal forms. The diagnosis is based on clinical appearance and confirmed by CD1a positivity and / or immunohistochemistry. We report the case of a male child of 3 months with two different presentations of Langerhans cell-histiocytosis (LCH) at different times. The first presentation was classified as a self-healing LCH (formerly known as Hashimoto-Pritzker). The last presentation, although clinically suggestive of Letterer-Siwe (former designation), was not associated with systemic disease. This emphasizes that LCH cannot be compartmentalized into four groups, but considered a single disease with a wide spectrum of clinical presentations. This case underscores the importance of frequent and long-term follow-up of these patients.