Ossifying Fibromyxoid Tumor - A Rare Case Report and Review of Literature

骨化性纖維黏液樣腫瘤──罕見案例報告及文獻回顧

Chih-Chao Chuang(莊智超) ； Chih-Hsueh Chen(陳志學) ； Mei-Chun Chen(陳梅君)

《臺灣整形外科醫學會雜誌》 32卷2期 (2023/06) Pp. 155-163

摘要

Background: Ossifying fibromyxoid tumor (OFMT), a rare soft tissue neoplasm, has slow clinical progression but has a potential for malignancy. The histological features of OFMT are similar to those of benign or malignant soft tissue tumors, including schwannomas or fibromyxoid sarcomas. Although the epidemiology and variable characteristics of OFMT have been documented, there is a need for increased awareness of its clinical and histological features to improve the diagnosis and clinical management of this rare tumor. Aim and Objectives: We present a rare case of a patient with OFMT according to its clinical pattern, histological features, immunohistochemical findings, and genetic characteristics. A literature review was conducted to determine the epidemiology and variable characteristics of this rare tumor. Materials and Methods: The patient was a 50-year-old male with a tumor in the deep space of the right posterior thigh, without pain and distal numbness. Computed tomography (CT) showed a heterogenous soft tissue tumor with calcification in the deep muscle near the sciatic nerve. The pathologic findings confirmed the diagnosis of OFMT. Results: Microscopically, the OFMT showed a multinodular structure with an incomplete peripheral shell of woven and lamellar bones. S100 and CD10 were immunoreactive upon immunohistochemical staining. The PHF1 translocation was identified, which supported the diagnosis of OFMT. Conclusion: Previous studies classified OFMT as typical, atypical, or malignant according to the histological features. A typical OFMT has a low recurrence rate and low risk of metastasis. The local recurrence and metastatic rates of malignant OFMT can be as high as 60%. Surgical excision with close follow-up is recommended owing to the possible local recurrence or distant metastasis, especially in patients with malignant OFMT.

關鍵字

ossifying fibromyxoid tumor ； S100 protein ； PHF1 gene translocation

並列摘要

背景：骨化性纖維黏液樣腫瘤（ossifying fibromyxoid tumor, OFMT）是一種具有潛在惡性變化的罕見軟組織腫瘤，好發於成年男性，肢體是最常見的位置，OFMT和某些良性或惡性的軟組織腫瘤，例如神經鞘瘤或惡性纖維黏液樣肉瘤，有相似的組織學表現。正確的診斷以及了解其臨床和組織學特色有助於對此一罕見腫瘤的認識。目的及目標：本篇提出骨化性纖維黏液樣腫瘤的案例報告並呈現其臨床表徵、組織學、免疫組織化學染色及基因特徵，並藉由文獻回顧來進一步的認識此疾病。材料及方法：50歲男性，右後大腿深部腫瘤，臨床上沒有疼痛或遠端肢體麻木症狀。下肢電腦斷層顯示一鈣化的異質性軟組織腫瘤，位於深部肌肉並貼著坐骨神經。腫瘤完整性切除後，病理報告證實診斷為骨化性纖維黏液樣腫瘤。結果：OFMT的病理特色為多發性結節狀的不完整周邊骨殼。免疫組織化學染色顯示S100和CD10為免疫陽性，PHF1基因轉位也支持OFMT的診斷。文獻回顧指出OFMT可依據組織學特色分為典型、非典型及惡性三類。典型OFMT復發率低且罕見轉移。惡性OFMT的復發及轉移率可能高達60%。結論：OFMT為具有多樣化組織病理特色，及潛在惡性變化可能的軟組織腫瘤。正確的診斷並依據組織學特色分類對疾病治療是很重要的。手術切除後需搭配密切的術後追蹤，以防可能的局部復發或遠端轉移，尤其是惡性OFMT。