Parekh Vishwas, Guerrero Cesar E, Knapp Charles F, Elmets Craig A, McKay Kristopher M
Departments of *Pathology, and †Dermatology, University of Alabama at Birmingham, Birmingham, AL.
Am J Dermatopathol. 2016 Jan;38(1):56-62. doi: 10.1097/DAD.0000000000000370.
Syringocystadenocarcinoma papilliferum (SCACP) is an extremely rare adnexal neoplasm, believed to arise in a preexisting nevus sebaceus of Jadassohn (NSJ) through a multistep progression process. This hypothetical process involves an NSJ giving rise to syringocystadenoma papilliferum, which then presumably undergoes malignant transformation in rare circumstances to give rise to SCACP in situ, which finally progresses to an invasive SCACP. Of the 30 SCACP cases reported so far, none have documented the process from a birthmark to the final invasive lesion, with histological evidence of each step, in a single tumor. Here, the authors report just such a case. A 74-year-old man presented with a recently enlarging birthmark on the scalp. Excisional biopsy showed an invasive SCACP, in the background of SCACP in situ, syringocystadenoma papilliferum, and NSJ. Furthermore, this tumor showed a concurrent pigmented trichoblastoma and histological evidence of lymphovascular invasion, events that have not been documented with SCACP. Interestingly, all these component lesions were present on a single histological section of this solitary tumor. Regional lymph node metastasis, a rare occurrence in SCACP, was also present in this remarkable case. The authors discuss the implications of these findings in light of the review of relevant literature.
乳头状汗管囊腺癌（SCACP）是一种极其罕见的附件肿瘤，被认为是通过多步骤进展过程起源于预先存在的 Jadassohn 皮脂腺痣（NSJ）。这个假设过程包括 NSJ 发展为乳头状汗管囊腺瘤，后者在罕见情况下可能发生恶性转化，形成原位 SCACP，最终发展为浸润性 SCACP。在迄今为止报道的 30 例 SCACP 病例中，没有一例记录了单个肿瘤从胎记到最终浸润性病变的全过程，且缺乏每个步骤的组织学证据。在此，作者报告了这样一例病例。一名 74 岁男性因头皮上一个近期增大的胎记就诊。切除活检显示为浸润性 SCACP，背景中有原位 SCACP、乳头状汗管囊腺瘤和 NSJ。此外，该肿瘤同时伴有色素性毛母细胞瘤以及淋巴管侵犯的组织学证据，这些情况在 SCACP 中尚未见报道。有趣的是，所有这些组成性病变都出现在这个孤立肿瘤的单个组织学切片上。区域淋巴结转移在 SCACP 中很少见，在这个特殊病例中也存在。作者结合相关文献综述讨论了这些发现的意义。
