Kudoh Kazuhiro, Itabashi Chieko, Arai Eiichi, Ohshika Shusa, Mizukami Hiroki
Department of Pathology and Molecular Medicine, Hirosaki University, Hirosaki, Japan.
Department of Pathology, Saitama Medical University International Medical Center, Saitama, Japan.
J Surg Case Rep. 2021 Dec 11;2021(12):rjab472. doi: 10.1093/jscr/rjab472. eCollection 2021 Dec.
A 31-year-old man with posterior neck mass visited a hospital. The mass recurred four times on the same location during the past 6 years. Needle biopsy diagnosis was suspicious for benign stromal tumor. Tumor excision was performed 3 months after the biopsy. The tumor size was 8.3 × 4.5 cm and was located at subcutaneous tissue. Histologically, main tumor cells showed comma-shaped nuclei, which are same as neurofibroma. Immunohistochemically, tumor cells were positive for vimentin, CD34, but were negative for S-100. Fluorescence hybridization analysis disclosed a split signal of PDGFB gene. Reverse transcriptase-polymerase chain reaction clarified COL1A1 exon 47/PDGFB exon 2 chimeric gene. Final diagnosis was dermatofibrosarcoma protuberans (DFSP) with neurofibromatous change. DFSP with neurofibromatous change is rare and could be misdiagnosed as benign tumor, especially in a biopsy specimen. Molecular diagnosis is a promising aid in a challenging case and in biopsy specimens.
一名31岁的男性因后颈部肿物前往医院就诊。在过去6年中，该肿物在同一部位复发了4次。针吸活检诊断怀疑为良性间质瘤。活检3个月后进行了肿瘤切除。肿瘤大小为8.3×4.5厘米，位于皮下组织。组织学上，主要肿瘤细胞显示逗号状核，与神经纤维瘤相同。免疫组织化学检查显示，肿瘤细胞波形蛋白、CD34呈阳性，但S-100呈阴性。荧光杂交分析显示血小板衍生生长因子B（PDGFB）基因有分裂信号。逆转录聚合酶链反应明确了1型胶原蛋白α1（COL1A1）外显子47/血小板衍生生长因子B外显子2嵌合基因。最终诊断为伴有神经纤维瘤样改变的隆突性皮肤纤维肉瘤（DFSP）。伴有神经纤维瘤样改变的DFSP很罕见，可能会被误诊为良性肿瘤，尤其是在活检标本中。分子诊断在具有挑战性的病例和活检标本中是一种很有前景的辅助手段。
