Infection in a Traveler Returning From India.

We report a case of infection in a US tourist returning from India and the Himalayas. This case highlights a need for awareness of various species endemic to India and the importance for physicians to consider rickettsial diseases in returning travelers with eschar or rash-associated febrile illnesses.

Cutaneous Rosai-Dorfman disease: comprehensive review of cases reported in the medical literature since 1990 and presentation of an illustrative case.

Background: The latest comprehensive review of primary cutaneous Rosai-Dorfman disease was published as part of an exhaustive survey of sinus histiocytosis with massive lymphadenopathy in 1990. Since then, much progress has been made in the understanding of malignant lymphoma and benign disorders of lymphoid and histiocytic origin.

Objective: We reviewed cases of primary cutaneous Rosai-Dorfman disease published since 1990 and discuss their clinical and pathologic features, comparing them with cases of systemic Rosai-Dorfman disease.

Histiocytic sarcoma with secondary involvement of the skin and expression of CD1a: evidence of indeterminate cell differentiation?

Background: Histiocytic sarcoma is an exceedingly rare malignant neoplasm composed of cells with a monocyte/macrophage phenotype. In the current nosology of histiocytic neoplasms, histiocytic sarcoma is separate from indeterminate cell histiocytosis, a generally benign disorder characterized by proliferation of a CD1a+ and S-100+ population of cells lacking Birbeck granules usually limited to the skin.

Methods: We present a case of histiocytic sarcoma in a 64-year-old man presenting as a peritonsillar mass and secondarily involving the skin.

A patient with extensive stem cell factor-induced hyperpigmentation.

Stem cell factor (SCF) is a cytokine that stimulates development of erythroid precursors and, consequently, may have potential importance in the treatment of certain anemias. We report a case of a young woman with Diamond-Blackfan anemia who received SCF treatment. One effect of SCF treatment is cutaneous hyperpigmentation at the injection site.