Department of Pathology, Nakagami Hospital, Noborikawa, Okinawa City, Okinawa, 904-2195, Japan.
Genomics Unit, Keio Cancer Center, Keio University School of Medicine, Tokyo, Japan.
Virchows Arch. 2021 Aug;479(2):401-405. doi: 10.1007/s00428-020-02958-7. Epub 2020 Nov 5.
Breast spiradenoma is extremely rare, with only 4 cases reported previously. We describe an instructive case of breast spiradenoma resembling adenoid cystic carcinoma (AdCC). A 71-year-old woman underwent excisional biopsy of a breast mass after a conclusive diagnosis was unable to be obtained from core needle biopsy showing an AdCC-like pattern. Histopathologically, the lesion demonstrated solid and cribriform foci comprising basaloid cells, luminal cells, and eosinophilic hyaline material, reminiscent of solid-basaloid AdCC, alongside convoluted lumens, stromal edema, lymphocytic infiltration, and c-kit negativity. On molecular analysis, neither MYB fusion genes nor CYLD gene abnormalities were identified. These results were supportive of spiradenoma. Salivary gland- and skin adnexal-type tumors are challenging to diagnose due to morphological overlaps. This case, highlighting histopathological and molecular features, shows that breast spiradenoma can be a diagnostic pitfall among the differential diagnoses of AdCC.
乳腺螺旋腺瘤极其罕见，既往仅报道过 4 例。我们描述了 1 例具有腺泡状囊性癌（AdCC）特征的乳腺螺旋腺瘤。1 例 71 岁女性，在核心针活检提示 AdCC 样模式但无法明确诊断后，行乳房肿块切除术。组织病理学上，病变显示出实性和筛状灶，包含基底样细胞、腔细胞和嗜酸性透明物质，类似于实性基底样 AdCC，同时伴有迂曲的腔、间质水肿、淋巴细胞浸润和 c-kit 阴性。分子分析未发现 MYB 融合基因或 CYLD 基因异常。这些结果支持螺旋腺瘤的诊断。由于形态学重叠，涎腺和皮肤附属器肿瘤的诊断具有挑战性。本病例突出了其组织病理学和分子特征，表明乳腺螺旋腺瘤在 AdCC 的鉴别诊断中可能是一个诊断陷阱。
