Rosai–Dorfman disease is a non Langerhans cell histiocytosis in which histiocytes accumulate excessively, classically presenting as massive, painless bilateral lymphadenopathy. However, isolated cutaneous disease is extremely rare. Diagnosis requires biopsy, showing sinusoids filled with numerous large histiocytes, with immunohistochemistry positive for S100, CD68, CD163 and negative for CD1a, CD207. It is a self-limited disease - up to half of patients experience spontaneous remission. Surgical excision is a highly curative treatment for unifocal lesions, with cure rates up to 80%. Other therapies such as methotrexate, imatinib, rituximab, vemurafenib, isotretinoin, thalidomide, or systemic corticosteroids may be used, but recurrence rates reach around 50%. This case involves a 51 year old woman from the capital of Bolivia (Sucre), with a 1 month history of a lesion in the left temporal region that had enlarged following manipulation. On segmental physical examination, there was a firm, erythematous violaceous nodule in the left temporal region measuring 1.5 × 1 cm. It was non tender to palpation and fixed to deeper planes. Biopsy of the lesion revealed dermal proliferation of histiocytic cells, immunohistochemically positive for S100 and Ki 67, and focally reactive in cells for Bcl 2, CD20, CD3, and Bcl 6. A diagnosis of cutaneous Rosai–Dorfman disease was established. The lesion was surgically excised, and at 3 month follow up, there was no evidence of recurrence.

I am a dermatologist who graduated two years ago in La Paz, Bolivia. I completed my residency at Hospital Obrero No. 1. I hold diplomas in Clinical Dermatology and Oncologic Dermatology, as well as a Master’s degree in Aesthetics, Nutrition, and Anti Aging. During my training, I served as a speaker at numerous national and international conferences, presented poster abstracts, and contributed papers to indexed international journals. Currently, I practice at the Caja Nacional de Salud and am a member of the Dermaclinic team in La Paz.