Muraoka Erika, Kato Ikuma, Matsumura Mai, Arai Yasuhiro, Suenaga Jun, Yamanaka Shoji, Fujii Satoshi
Department of Diagnostic Pathology, Yokohama City University Hospital, Yokohama, Japan.
Department of Molecular Pathology, Yokohama City University, Graduate School of Medicine, Yokohama, Japan.
Int J Surg Pathol. 2023 Oct;31(7):1414-1419. doi: 10.1177/10668969231152577. Epub 2023 Feb 19.
Biphenotypic sinonasal sarcoma is a newly established tumor entity that is associated with distinct clinicopathological findings. Biphenotypic sinonasal sarcoma is a rare, low-grade spindle cell sarcoma that arises in middle-aged females, exclusively in the sinonasal tract. A fusion gene involving is detected in most biphenotypic sinonasal sarcomas, which aids in its diagnosis. Here, we report a case of biphenotypic sinonasal sarcoma with its cytological findings. The patient was a 73-year-old woman who presented with purulent nasal discharge and dull pain in the left cheek area. Computed tomography showed a mass extending from the left nasal cavity to the left ethmoid sinus, the left frontal sinus, and the frontal skull base. She underwent a combined transcranial and endoscopic approach for en bloc resection with a safety margin. Histologically, spindle-shaped tumor cells have been thought to proliferate mainly in the subepithelial stroma. Here, nasal mucosal epithelial hyperplasia was noted, and the tumor had invaded the bone tissue accompanying the epithelial cells. Fluorescence hybridization (FISH) analysis showed a rearrangement, and next-generation sequencing identified a fusion. Based on FISH, split signals were observed not in respiratory cells but in stromal cells. This indicated that respiratory cells were non-neoplastic. In the diagnosis of biphenotypic sinonasal sarcoma, the inverted growth of the respiratory epithelium can be a diagnostic pitfall. FISH analysis using a break-apart probe is helpful not only for an accurate diagnosis but also for detecting the true neoplastic cells.
双表型鼻窦肉瘤是一种新确立的肿瘤实体，与独特的临床病理表现相关。双表型鼻窦肉瘤是一种罕见的低级别梭形细胞肉瘤，发生于中年女性，仅见于鼻窦。大多数双表型鼻窦肉瘤中可检测到一种涉及……的融合基因，这有助于其诊断。在此，我们报告一例双表型鼻窦肉瘤及其细胞学表现。患者为一名73岁女性，表现为脓性鼻涕和左侧面颊区钝痛。计算机断层扫描显示一个肿块从左鼻腔延伸至左筛窦、左额窦和额颅底。她接受了经颅和内镜联合入路的整块切除并保留安全切缘。组织学上，梭形肿瘤细胞被认为主要在黏膜下基质中增殖。在此，可见鼻黏膜上皮增生，肿瘤伴随上皮细胞侵犯骨组织。荧光原位杂交（FISH）分析显示……重排，二代测序鉴定出一种……融合。基于FISH，分裂信号并非在呼吸细胞中而是在基质细胞中观察到。这表明呼吸细胞是非肿瘤性的。在双表型鼻窦肉瘤的诊断中，呼吸上皮的倒置生长可能是一个诊断陷阱。使用……断裂分离探针的FISH分析不仅有助于准确诊断，还能检测真正的肿瘤细胞。
