The case history of a patient treated for unilateral hereditary retinoblastoma who subsequently developed malignant melanoma and eosinophilic granuloma is presented. Although the association between retinoblastoma and second malignancies including malignant melanoma is established, we have found no reports of third malignancies occurring in such individuals.

An 87-year-old white woman who was diagnosed in 1980 with malignant melanoma (MM) on the plantar aspect of her right foot (invasion, Clark level II; thickness, 0.7 mm) was referred to the dermatology clinic at the University of Texas Medical Branch, Galveston, 10 years after undergoing the initial surgery. A nonpigmented 1.1 \ m=x\0.6-cm shallow erosion overlaying the metatarsophalangeal joint ( Fig 1) was observed. Multiple 3-mm punch biopsy specimens of the erosion revealed an undifferentiated tumor adjacent to the epidermis that invaded the superficial dermis. Immunoperoxidase staining was positive for S100 protein and negative for keratin. The lymph nodes were not palpable, and no signs and symptoms of visceral metastatic disease were observed. Findings from her blood chemistry tests were within normal limits, except for borderline elevation of the alkaline phosphatase (279 U/L; normal, 68 to 243 U/L) and lactic dehydrogenase levels (207 U/L; normal, 109 to 193 U/L). The chest roentgenogram showed no evidence of metastatic tumor. The patient refused further evaluation for metastatic disease. She was classified as having acral lentiginous amelanotic MM of the right foot. After full dis¬ cussion of the treatment options available to her and the