Department of Dermatology, Kansai Medical University Medical Center, Osaka, Japan.
J Dermatol. 2019 May;46(5):440-443. doi: 10.1111/1346-8138.14829. Epub 2019 Feb 27.
A 65-year-old Japanese man presented with a dome-shaped nodule, the base of which was contiguous with a dull brown plaque, on the left leg. After local excision of the cutaneous lesion and left inguinal lymph node dissection, several dermal and subcutaneous nodules developed successively on the left lower extremity. Hematoxylin-eosin staining of the primary cutaneous lesion demonstrated uniform neoplastic cells arranged in a trabecular pattern extending from the dermis to subcutis. Mitotic figures were abundant. Although the overlying epidermis was substantially intact, the Merkel cells had invaded the epidermis, resulting in Pautrier-like microabscesses. The hyperplastic epidermis adjacent to the nodule consisted of abnormally growing atypical keratinocytes. The enlarged left inguinal lymph node and successive secondary nodules contained Merkel cells similar to those in the primary nodule. Immunohistochemically, most tumor cells were positive for CAM5.2, synaptophysin, chromogranin A, CD56 and vimentin. The tumor cells in the left inguinal lymph node were positive for CAM5.2, synaptophysin and cytokeratin 20 but negative for CM2B4, and less than 1% of the cells expressed programmed cell death ligand 1. The patient was treated with avelumab, which showed significant efficacy against the in-transit recurrence. Two months later, all nodules had disappeared completely. We describe a case of in-transit recurrence of Merkel cell carcinoma that was associated histologically with Bowen's disease and was successfully treated with avelumab. Although accumulation of additional cases is needed, avelumab therapy may be a useful treatment for in-transit recurrence of Merkel cell carcinoma.
一位 65 岁的日本男性，左下肢出现一个呈圆顶状结节，其基底与一个暗褐色斑块相连。在进行皮肤病变的局部切除和左侧腹股沟淋巴结清扫术后，左下肢相继出现多个皮肤和皮下结节。原发皮肤病变的苏木精-伊红染色显示，均匀的肿瘤细胞呈小梁状排列，从真皮延伸至皮下组织。有丝分裂象丰富。虽然表皮大部分完整，但默克尔细胞已侵犯表皮，导致类似于 Pautrier 的微脓肿。邻近结节的增生表皮由异常生长的非典型角朊细胞组成。增大的左侧腹股沟淋巴结和相继的继发性结节含有与原发结节相似的默克尔细胞。免疫组化染色显示，大多数肿瘤细胞对 CAM5.2、突触素、嗜铬粒蛋白 A、CD56 和波形蛋白呈阳性。左侧腹股沟淋巴结中的肿瘤细胞对 CAM5.2、突触素和细胞角蛋白 20 呈阳性，但对 CM2B4 呈阴性，不到 1%的细胞表达程序性细胞死亡配体 1。该患者接受avelumab 治疗，对转移复发显示出显著疗效。两个月后，所有结节完全消失。我们描述了一例 Merkel 细胞癌的转移复发病例，该病例与 Bowen 病在组织学上相关，并成功地接受了avelumab 治疗。尽管需要积累更多的病例，但avelumab 治疗可能是 Merkel 细胞癌转移复发的一种有效治疗方法。
