Ortiz Salvador José María, Subiabre-Ferrer Daniela, Alegre de Miquel Victor
Department of Dermatology, General Hospital of Valencia, Valencia, Spain.
Indian J Dermatol. 2019 May-Jun;64(3):251. doi: 10.4103/ijd.IJD_608_16.
Primary cutaneous neuroendocrine carcinoma (PCNC), previously known as Merkel cell carcinoma (MCC), is a rare tumor of the skin with aggressive behavior and poor prognosis. Typically, PCNC is positive for Cytokeratin-20 (CK20) and negative for Thyroid Transcription Factor-1 (TTF-1). Rarely, CK-20 negative and TTF-1 positive PCNC have been described. We present the case of two patients with skin lesions histologically compatible with MCCs and a behavior characteristic of this disease, but with expression of TTF-1 instead of CK-20. In conclusion, there are increasing reports of TTF1+ CK20- skin lesions without signs of systemic disease which behave clinically and prognostically like a PCNC. The origin of these TTF1 tumors are, to date, unknown.
原发性皮肤神经内分泌癌（PCNC），以前称为默克尔细胞癌（MCC），是一种罕见的皮肤肿瘤，具有侵袭性且预后较差。通常，PCNC对细胞角蛋白20（CK20）呈阳性，对甲状腺转录因子1（TTF-1）呈阴性。很少有报道称存在CK-20阴性且TTF-1阳性的PCNC。我们报告了两例皮肤病变患者，其组织学表现与MCC相符，具有该病的行为特征，但表达的是TTF-1而非CK-20。总之，越来越多的报道称存在TTF1阳性、CK20阴性且无全身疾病迹象的皮肤病变，其临床行为和预后类似于PCNC。迄今为止，这些TTF1肿瘤的起源尚不清楚。
