Abstract：
UNASSIGNED: Cutaneous squamomelanocytic tumor (SMT) is an exceedingly rare cutaneous malignancy characterized by the presence of both squamous cell carcinoma and malignant melanoma within a single tumor. SMT typically presents clinically as keratotic skin papulonodules, most commonly occurring on the face, scalp, or other sun-exposed areas of middle-aged to elderly White male patients. Owing to the rare nature of this tumor, the histogenesis and prognosis remain relatively unclear. Histopathological examination of the tangential biopsy revealed an invasive cutaneous malignancy consisting of 2 distinct yet closely associated atypical cell populations: (1) a population of atypical squamoid epithelial cells arranged in cords and keratin pearls and (2) a population consisting of atypical, spindled cells with fine melanin pigment arranged in confluent sheets. Both populations of atypical cells emanated in an invasive pattern from the underside of the overlying epidermis into the deep dermis. Squamomelanocytic tumors are among the rarer types of collision tumors between 2 malignant lesions as most are basomelanocytic. For most reported SMTs, the melanoma population comprises epithelioid cell morphology, whereas our tumor is composed of spindled cell morphology. In this article, we exemplify a unique case of SMT in an 87-year-old male patient.
摘要：
未经证实：皮肤鳞状细胞瘤（SMT）是一种极为罕见的皮肤恶性肿瘤，其特征是在单个肿瘤中同时存在鳞状细胞癌和恶性黑色素瘤。SMT通常在临床上表现为角化性皮肤丘疹结节，最常见于面部，头皮,或其他暴露在阳光下的中老年白人男性患者。由于这种肿瘤的罕见性质，组织发生和预后仍相对不清楚。切向活检的组织病理学检查显示，侵袭性皮肤恶性肿瘤由2个不同但密切相关的非典型细胞群组成：（1）排列在绳索和角蛋白珍珠中的非典型鳞状上皮细胞群和（2）由非典型，具有细黑色素色素的纺锤状细胞，排列成汇合片。两种非典型细胞都以侵入性的方式从上覆的表皮的下侧散发到深层真皮中。鳞状细胞瘤是2种恶性病变之间罕见的碰撞肿瘤类型，因为大多数是碱性粒细胞。对于大多数报告的SMT，黑色素瘤群体包括上皮样细胞形态，而我们的肿瘤是由纺锤状细胞形态组成的。在这篇文章中,我们在一名87岁的男性患者中举例说明了一例独特的SMT病例.
