Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA.
Am J Surg Pathol. 2012 Oct;36(10):1509-15. doi: 10.1097/PAS.0b013e31825e63bf.
Fibroblastic connective tissue nevus (FCTN) represents a rare and distinct benign cutaneous mesenchymal lesion of fibroblastic/myofibroblastic lineage, which broadens the spectrum of lesions presently recognized as connective tissue nevus. A series of 25 cases of FCTN has been analyzed to further characterize the clinicopathologic spectrum and immunohistochemical features of this entity. Sixteen patients were female (64%) and 9 were male (36%), with age at presentation ranging from 1.5 months to 58 years (median, 10 y). Most patients presented with a solitary, slowly growing, painless plaque-like or nodular skin lesion. Eleven cases (44%) arose on the trunk, 9 (36%) on the head and neck, and 5 (20%) on the limbs. The lesion was present for a median duration of 11.5 months (mean, 13.2 mo). Grossly, the lesions were tan-brown to tan-white, smooth, and firm. Their size ranged from 0.3 to 2.0 cm in greatest dimension (mean size, 0.67 cm; median, 0.6 cm). All tumors showed poor circumscription and were situated primarily in the reticular deep dermis, extending into the superficial subcutis in 13 cases (52%). The lesion was associated with papillomatous epidermis in 17 cases (70%) and the presence of adipose tissue in the reticular dermis in 14 cases (60.9%). All tumors were composed of a proliferation of bland intradermal fibroblastic/myofibroblastic cells with indistinct palely eosinophilic cytoplasm and tapering nuclei, with no significant cytologic atypia or pleomorphism, arranged in short-intersecting fascicles and entrapping appendages. No mitoses were identified. Immunostains showed positivity for CD34 in 20 of 23 cases (87%) and weak focal positivity for smooth muscle actin in 9 of 19 cases (47%). No case stained positively for desmin or S100 protein. Clinical follow-up was obtained for 14 patients (median duration, 4 y). No tumor recurred locally, even when surgical excision was incomplete. No lesion metastasized. FCTN occurs most commonly as a plaque on the trunk and head/neck of children, involves deep dermis and superficial subcutis, and stains mainly for CD34. FCTN most likely represents a localized developmental dermal anomaly; it is entirely benign and should not be confused with dermatofibrosarcoma protuberans or other neoplasms such as dermatomyofibroma.
纤维母细胞性连接组织痣（fibroblastic connective tissue nevus，FCTN）是一种罕见且独特的良性皮肤间叶病变，属于纤维母细胞/肌纤维母细胞谱系，扩大了目前被认为是结缔组织痣的病变谱。我们分析了 25 例 FCTN 病例，以进一步描述该病变的临床病理谱和免疫组织化学特征。16 例患者为女性（64%），9 例为男性（36%），发病年龄为 1.5 个月至 58 岁（中位数 10 岁）。大多数患者表现为单发、生长缓慢、无痛性斑块样或结节状皮肤病变。11 例（44%）发生于躯干，9 例（36%）发生于头颈部，5 例（20%）发生于四肢。病变持续时间中位数为 11.5 个月（平均 13.2 个月）。大体上，病变呈棕褐色至棕白色，光滑且坚实。其最大直径为 0.3 至 2.0cm（平均大小 0.67cm；中位数 0.6cm）。所有肿瘤边界不清，主要位于网状真皮深部，13 例（52%）延伸至浅层皮下组织。17 例（70%）病变伴有乳头状表皮，14 例（60.9%）病变伴有网状真皮内脂肪组织。所有肿瘤均由弥漫性真皮内纤维母细胞/肌纤维母细胞增生组成，细胞胞浆淡嗜酸性，细胞核呈楔形，无明显的细胞学异型性或多形性，呈短交叉束状排列，并包绕附属物。未见有丝分裂象。免疫组化染色显示，23 例中有 20 例（87%）CD34 阳性，19 例中有 9 例（47%）平滑肌肌动蛋白弱阳性阳性。没有病例 desmin 或 S100 蛋白阳性染色。对 14 例患者进行了临床随访（中位数随访时间 4 年）。即使手术切除不完全，也未见局部肿瘤复发，也未见转移。FCTN 最常见于儿童的躯干斑块和头颈部，累及真皮深部和浅层皮下组织，主要表达 CD34。FCTN 可能代表一种局限性的皮肤发育异常，它完全是良性的，不应与隆突性皮肤纤维肉瘤或其他肿瘤（如皮肤纤维瘤）相混淆。
