[Osteoid osteoma at the end of the phalanx of the big toe]

A 20-year-old man with persistent pain in the left big toe associated with broadening, thickening and discolouration of the toenail had been treated unsuccessfully for 21 months by surgical measures (wedge excision, avulsion of the nail) and local applications (antibiotics, antimycotics, disinfectants). A radiograph of the left big toe showed an area of calcification 0.5 cm in diameter at the base of the terminal phalanx. It was surrounded by a narrow zone of transradiancy and projected upwards above the margin of the bone. Among the diagnostic possibilities were osteomyelitis and osteoid osteoma. Biopsy revealed the latter, and the patient was cured by "en bloc" resection of the tumour. This case shows that abnormalities of nail growth of the kind commonly associated with paronychia may occasionally be due to a neoplastic lesion in the terminal phalanx.