Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany; and.
Dermatopathology, Bodensee, Friedrichshafen, Germany.
Am J Dermatopathol. 2021 Dec 1;43(12):965-969. doi: 10.1097/DAD.0000000000002049.
Syringocystadenocarcinoma papilliferum (SCACP), the malignant counterpart of syringocystadenoma papilliferum (SCAP), is an extremely rare malignant adnexal neoplasm. It is described by the World Health Organization as a malignant transformation of SCAP occurring in middle-aged to elderly individuals with a predilection for the head and neck. SCACP seems to arise from a long-standing syringocystadenoma probably on a background of nevus sebaceous (NS) through a multistep progression. A 75-year-old man was referred to our department with a long-standing NS with a recent newly developing nodule on his scalp. The tumor was excised. On histology, the overall architecture of the tumor still resembled an unusual SCAP within NS but simultaneously showed transition to syringocystadenocarcinoma papilliferum in situ and invasive SCACP as recognizable by the presence of areas of nuclear atypia, increased proliferative activity, and infiltrative growth. In summary, we report an extremely rare case of an invasive SCACP of the scalp that demonstrates histological evidence for all transitive steps in the hypothetical multistep progression from NS to invasive SCACP in one single lesion. The implications of these findings are discussed in the light of the relevant literature.
汗管囊腺癌乳头状瘤（SCACP）是汗管囊腺瘤乳头状瘤（SCAP）的恶性对应物，是一种极其罕见的恶性附属器肿瘤。世界卫生组织将其描述为 SCAP 的恶性转化，发生在中年至老年人群中，好发于头颈部。SCACP 似乎起源于长期存在的汗管囊腺瘤，可能在皮脂腺痣（NS）的背景下通过多步进展发生。一位 75 岁男性因头皮上长期存在的 NS 并伴有近期新出现的结节而被转至我科。肿瘤被切除。组织学上，肿瘤的整体结构仍类似于 NS 内的不寻常 SCAP，但同时显示出向原位汗管囊腺癌乳头状瘤和可识别的侵袭性 SCACP 的转变，其特征为存在核异型性、增殖活性增加和浸润性生长区域。总之，我们报告了一例极其罕见的头皮侵袭性 SCACP 病例，该病例在单个病变中显示出从 NS 到侵袭性 SCACP 的假设多步进展的所有过渡步骤的组织学证据。根据相关文献，讨论了这些发现的意义。
