Department of Pathology, University of Tennessee Medical Center, Knoxville, TN.
Department of Pathology, Aurora Diagnostics/Sonic Healthcare, Salem, OR; and.
Am J Dermatopathol. 2023 Aug 1;45(8):e58-e60. doi: 10.1097/DAD.0000000000002489. Epub 2023 Jun 28.
Merkel cell carcinoma (MCC) is an uncommon aggressive primary cutaneous neuroendocrine tumor usually arising on sun exposed skin of older patients. Most Merkel cell carcinomas are diagnosed as invasive tumors with only rare cases of MCC in situ (MCCIS) reported. MCCs are often associated with other cutaneous neoplasms and more recently have been described in association with cystic lesions, albeit rarely. We present a unique case of an 80-year-old male with a slow growing nodular lesion on the right buttock that on excision demonstrated MCCIS arising within an infundibular cyst with unusual reticulated infundibulocystic proliferation. The MCCIS was intimately associated with the infundibulocystic proliferation and demonstrated immunopositivity for CK20, CD56, AE1/AE3, synaptophysin, and Merkel cell polyoma virus. The confinement of the MCC to the epithelium together with the Merkel cell polyoma virus positivity further supports the assumption that viral positive MCC may derive from epithelial linage.
默克尔细胞癌（Merkel cell carcinoma，MCC）是一种罕见的侵袭性原发性皮肤神经内分泌肿瘤，通常发生在暴露于阳光的老年患者皮肤上。大多数 Merkel 细胞癌被诊断为侵袭性肿瘤，仅有少数原位 Merkel 细胞癌（Merkel cell carcinoma in situ，MCCIS）的病例报道。Merkel 细胞癌常与其他皮肤肿瘤相关，最近也有报道与囊性病变相关，尽管很少见。我们报告了一例独特的病例，一名 80 岁男性右臀部有一个生长缓慢的结节性病变，切除后显示 MCCIS 发生在一个漏斗状囊肿内，伴有不寻常的网状漏斗状囊状增生。MCCIS 与漏斗状囊状增生密切相关，免疫组化显示 CK20、CD56、AE1/AE3、突触素和 Merkel 细胞多瘤病毒阳性。MCC 局限于上皮，同时 Merkel 细胞多瘤病毒阳性，进一步支持了病毒阳性 Merkel 细胞癌可能来源于上皮谱系的假设。
