Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, USA.
Department of Pathology, Gulhane Military Medical Academy and School of Medicine, Kecioren, Ankara, Turkey.
Ann Diagn Pathol. 2022 Feb;56:151868. doi: 10.1016/j.anndiagpath.2021.151868. Epub 2021 Nov 18.
Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine carcinoma of the skin, often associated with polyomavirus and ultra-violet light exposure. Immunosuppression is associated with increased risk of development of MCC, including that associated with hematolymphoid disorders such as chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). We sought to determine whether MCC arising in patients with hematologic disorders showed unique features. Searching archived material at three institutions, we identified 13 patients with MCC and at least one hematologic malignancy and 41 patients with MCC with no reported hematologic malignancy. CLL/SLL was the most common hematologic disorder in this setting (9/13 cases). Clinical history, variation in morphologic appearance, unusual site distribution and concern for progression of underlying hematologic disease all contributed to potential diagnostic challenges. Overlapping marker expression between MCC and hematologic neoplasms created potential diagnostic pitfalls (e.g. CD138, Pax5, TdT, Bcl2, CD56, and CD117). In addition, we newly identify expression of CD5 and LEF-1 in a subset of MCC, including in patients with CLL/SLL. MCC in patients with hematologic malignancy were more common in men (92% versus 59%, p < 0.05) and showed an unusual site predilection to non-sun exposed sites (3/13 on the buttocks) with none presenting on the face or scalp. By contrast, face or scalp lesions were common in MCC without an associated hematologic malignancy (17/41, p < 0.05). Our findings reaffirm the need for skin surveillance in the setting of immune deficiency and for vigilance to identify unusual presentations of MCC in patients with or without hematologic disorders.
默克尔细胞癌（Merkel cell carcinoma，MCC）是一种罕见但具有侵袭性的皮肤神经内分泌癌，常与多瘤病毒和紫外线暴露有关。免疫抑制与 MCC 发病风险增加相关，包括与血液淋巴系统疾病相关的风险，如慢性淋巴细胞白血病/小淋巴细胞淋巴瘤（chronic lymphocytic leukemia/small lymphocytic lymphoma，CLL/SLL）。我们试图确定血液系统疾病患者中发生的 MCC 是否具有独特的特征。通过在三个机构的存档材料中进行检索，我们共鉴定出 13 例至少患有一种血液恶性肿瘤的 MCC 患者和 41 例未报告血液恶性肿瘤的 MCC 患者。在这种情况下，CLL/SLL 是最常见的血液系统疾病（9/13 例）。临床病史、形态学表现的差异、不常见的部位分布以及对潜在血液系统疾病进展的关注，均促成了潜在的诊断挑战。MCC 与血液肿瘤之间重叠的标志物表达导致了潜在的诊断陷阱（例如 CD138、Pax5、TdT、Bcl2、CD56 和 CD117）。此外，我们还新发现了一组 MCC 中 CD5 和 LEF-1 的表达，包括 CLL/SLL 患者。血液恶性肿瘤相关 MCC 更常见于男性（92%比 59%，p<0.05），且具有不常见的非暴露于阳光部位的部位倾向（13 例中有 3 例在臀部），而无面部或头皮病变。相比之下，无相关血液恶性肿瘤的 MCC 中面部或头皮病变较为常见（41 例中有 17 例，p<0.05）。我们的研究结果再次证实，在免疫缺陷的情况下需要进行皮肤监测，并需要警惕在有无血液系统疾病的患者中识别 MCC 的不常见表现。
