Multiple basaloid cell hamartoma with alopecia and autoimmune disease (systemic lupus erythematosus).

We report a 22-year-old Japanese woman with multiple basaloid cell hamartoma with alopecia and autoimmune disease (systemic lupus erythematosus). She presented with infiltrated large annular, brown-violet, erythematous plaques with atrophic areas in the center on her right cheek, left abdomen and left knee. She also had progressive multiple follicular keratotic papules on her scalp, face, neck, and both axilla and hair loss from her scalp, eyebrow, and axilla. Serologically, rheumatoid factor (+ + +), rheumatoid arthritis hemagglutination test (x1280), and anti-nuclear antigen (x160) were positive. Histological findings of the annular lesion showed liquefaction degeneration of basal cells, lymphocytic infiltration around hair follicles and capillaries, and panniculitis with lymphoid cell infiltration, which was diagnosed as lupus erythematosus profundus. The histological findings of multiple follicular papular lesions of the scalp and neck showed aggregations of basaloid cells, partially with hair-bulb-like structures, which was diagnosed as trichoepithelioma. Taken together, the histogenesis of multiple basaloid cell hamartoma is thought to share the same basis with autoimmune disease.