Sea urchin injury in rare cases can produce tuberculoidgranuloma.The MP joint region of the volar side of the right thumb of a 53-year-old fisherwoman was penetrated by a sea urchin spine in September, 1981. On the following day local heat and swelling occurred in the volar side of the right hand. She was treated as having phlegmon and tenosynivitis for 2 months; thereafter the symptoms decreased, even though she was not cured. Three years later she came to our hospital because of pain, swelling and stiffness of the right thumb. Active ROM of the IP joint of the thumb was 5-10 degrees.
X-rays showed oval hyperlucent lesions approximately 5mm in diameter in the head of the proximal phalanx and base of the distal phalanx. The cortex was destroyed. After 6 months curettage was performed and the ROM was improved to 0-25 degrees afterwords. Microscopic examination of the tissue obtained by curettage showed tuberculoid granuloma with caseous necrosis. Ziel-Neelsen's stain demonstrated acid-fast bacilli which we think were mycobacterium marinum.