Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
Am J Surg Pathol. 2018 Mar;42(3):392-400. doi: 10.1097/PAS.0000000000001019.
Chondromyxoid fibroma (CMF) is a rare benign tumor, usually arising in the metaphysis of long bones in young adults. Occurrence in craniofacial bones presents a particular diagnostic challenge given its unusual location and resemblance to malignant mimics. We describe the clinicopathologic features of 25 cases of craniofacial CMF identified between 1999 and 2017. Patients were 14 men and 11 women, with median age of 44 years (range, 5 to 83 y). Sites of involvement were sphenoid (7), ethmoid (5), maxilla (3), occipital (2), nasal septum (2), palatine (2), temporal (2), orbit (1), and undisclosed skull (1). Tumor size ranged from 0.8 to 6.0 cm (median, 2.0 cm). Of the 21 tumors with available radiology, 15 arose on the bone surface with expansion into adjacent sinuses; 6 were intraosseous. Bony erosion/destruction was present in most (13/16) cases, and 7/12 showed calcification on imaging. Microscopically, most tumors showed a lobulated growth pattern with hypocellular central chondromyxoid areas and peripheral hypercellularity, though many samples were fragmented. Tumor cells had ovoid to tapered nuclei and abundant palely eosinophilic cytoplasm, frequently with stellate cell processes. Mitoses ranged from 0 to 2 per 10 high-power fields (median count, 0). None showed necrosis. Significant atypia was present in 2 cases, 1 of which was a previously radiated recurrence. Bone infiltration was present in 6 cases. Thirteen tumors had focal calcification, and 2 had foci of hyaline cartilage. All tumors were negative for keratin and GFAP (0/24), with frequent positivity for SMA (7/7) and occasional staining for EMA (5/24) and S-100 (2/24). Most patients underwent piecemeal excision or curettage (5/5 positive margins when reported). Follow-up data were available for 15 patients, and 5 suffered local recurrence. Craniofacial CMF poses diagnostic pitfalls including frequent aggressive radiologic features and lack of a specific immunophenotype. Tumors may recur, largely due to the difficulty of obtaining clear surgical margins in this anatomic region. Furthermore, propensity for local destruction and invasion can create significant morbidity.
软骨黏液样纤维瘤（chondromyxoid fibroma，CMF）是一种罕见的良性肿瘤，通常发生在年轻成人的长骨干骺端。由于其位置异常且与恶性肿瘤相似，因此发生在颅面骨中具有特殊的诊断挑战性。我们描述了 1999 年至 2017 年间确诊的 25 例颅面 CMF 的临床病理特征。患者为 14 名男性和 11 名女性，中位年龄为 44 岁（范围，5-83 岁）。受累部位为蝶骨（7 例）、筛骨（5 例）、上颌骨（3 例）、枕骨（2 例）、鼻中隔（2 例）、硬腭（2 例）、颞骨（2 例）、眼眶（1 例）和未披露的颅骨（1 例）。肿瘤大小为 0.8-6.0cm（中位数，2.0cm）。在有影像学资料的 21 例肿瘤中，15 例起源于骨表面，伴有向相邻窦腔的膨胀；6 例为骨内。大多数（13/16）病例存在骨侵蚀/破坏，12 例中有 7 例在影像学上显示钙化。大多数肿瘤表现为分叶状生长模式，中央软骨黏液样区细胞减少，周围细胞增多，但许多标本呈碎片状。肿瘤细胞有卵圆形至锥形核和丰富的淡嗜酸性细胞质，常伴有星状细胞突起。核分裂象为 0-2/10 高倍视野（中位数计数，0）。均未见坏死。2 例存在显著异型性，其中 1 例为既往放疗后复发。6 例存在骨浸润。13 例肿瘤有局灶性钙化，2 例有透明软骨灶。所有肿瘤均为角蛋白和 GFAP 阴性（0/24），平滑肌肌动蛋白（SMA）阳性率为 7/7，上皮膜抗原（EMA）和 S-100 阳性率分别为 5/24 和 2/24。大多数患者行部分切除或刮除术（当报告时，5 例阳性切缘）。15 例患者可获得随访资料，5 例患者局部复发。颅面 CMF 具有诊断陷阱，包括频繁出现侵袭性影像学特征和缺乏特定的免疫表型。肿瘤可能会复发，主要是由于在该解剖区域难以获得清晰的手术切缘。此外，局部破坏和侵袭的倾向会导致严重的发病率。
