Tumoral Calcinosis與Myositis Ossificans於一位全身性硬化症患者之前後消長

Reverse evolution of tumoral calcinosis and myositis ossificans in a patient with systemic sclerosis

營養不良性鈣質沉著症（dystrophic calcinosis）為全身性硬化症常見的併發症，易導致局部組織僵硬，影響關節肌肉功能，自發性發炎，甚而破裂與感染。鈣質沉著症可能於全身性硬化症緩解後，仍持續增長，不易治療。諸如warfarin, diltiazem, co1chicine, probenecid, EDTA,與steroid等藥物，尚無一致的療效。而異位性骨化（heterotopíc ossification）的成因可為遺傳性，神經性，或多數發生於外傷與外科手術後，肌肉不正常之反應性骨化現象（骨化性肌炎，myositis ossificans）。本篇病例報告描述一位58歲女性於罹患全身性硬化症七年後，表現輕度肺部纖維化，重度乾燥症，與全身多發性如腫瘤般的鈣質沉著（tumoral calcinosis）。經以warfarin維持凝血時間INR於2-2.5，長達四年之治療後，臨床與X光追蹤檢查顯示其鈣質沉著幾乎完全消失，取而代之為骨化性肌炎，文獻中至令尚無類似之病例報告。本病例提供warfarin有效治療鈣質沉著症之經驗，而鈣質沉著症與骨化性肌炎相對之消長，則顯示此二者不同之致病機轉。

A 58-year-old woman with diffuse systemic sclerosis (SSe) for 7 years presented with massive stony-hard tumoral calcinosis over her right shoulder and axilla, bilateral buttocks, and left thigh. The scleroderma had improved to a great extent and appeared mild. No abnormalities were revealed by routine hemogram, urinalysis, and blood chemistry. She was treated with warfarin (2.5 to 5 mg/day) to suppress synthesis of 4-carboxy-L-glutamic acid, the calcium-binding amino acid. The tumoral calcinosis improved slowly. Nevertheless, all the subcutaneous mass had completely resolved by the fourth year. Sequential radiographic studies showed marked resolution of the calcinosis but development of myositis ossificans (MO) next to the bones and joints of the previous calcinosis sites. Dystrophic calcinosis is commonly observed in patients with SSe, whereas MO has not been reported in patients with SSe. It was apparent that prolonged warfarin therapy effectively suppressed subcutaneous calcinosis, but did not prevent the development of MO. In addition, the reverse evolution of calcinosis and MO in this patient suggested that calcinosis and MO might have distinct etiopathogenesis.