黑色素细胞瘤（Melanophoroma）是爬行动物色素细胞的肿瘤，被认为是非常罕见的一类组织肿瘤，属于色素细胞瘤。本研究的目的是描述一例在野生的利希登斯滑鳞蛇（Philodryas olfersii）中发现的黑色素细胞瘤病例，该病例表现为头部皮肤中具有溃疡性结节的新生物。在神经学评估中，观察到一种本体感觉缺陷。进行了超声、X射线和质量细胞学检查。肿瘤的放射学和超声结果表明其有浸润性行为，细胞学则表明它是黑素细胞性肿瘤的可能诊断。根据检查结果和患者的临床情况，选择了安乐死。在剖检中，发现一个大小为4.5×2.5×2.0cm的结节，切面呈黑色，灰色区域呈杂斑状，浸润了软组织和骨骼，并从口腔蔓延到颈部肌肉。显微镜下观察到一种非界定的、非包膜的、侵袭性增生的肿瘤，细胞密度适中，主要由带有明显边界的纺锤形细胞和上皮样细胞聚集区组成。细胞具有丰富的细胞质，呈棕色到黑色（黑素细胞）颗粒状色素，与黑色素细胞瘤相符。据作者所知，这是对P. olfersii中黑色素细胞瘤的独特描述。© 2023年美国兽医临床病理学协会。

Melanophoroma is a neoplasm of reptilian pigment cells, considered uncommon and part of a group of neoplasms called chromatophoromas. The objective of this work was to describe a case of melanophoroma in a free-living Lichtenstein's green racer snake (Philodryas olfersii), presenting with an ulcerative nodular neoformation in the integument of the head region. In the neurologic evaluation, a proprioceptive deficit was observed. Ultrasound, X-ray, and mass cytology examinations were performed. Radiographic and ultrasound findings of the tumor indicated infiltrative behavior, and cytology indicated a presumptive diagnosis of a melanocytic neoplasm. Based on the results of the examinations and the patient's clinical condition, euthanasia was chosen. At necropsy, there was a nodule measuring 4.5 × 2.5 × 2.0 cm, with a blackish-colored cut surface, mottled by gray areas, which infiltrated soft tissue and bone, and extended dorsally from the mouth to the cervical musculature. On microscopy, a non-delimited, non-encapsulated, and invasive neoplastic proliferation was observed, with moderate cellularity, which was predominantly composed of fusiform cells with distinct borders and foci of epithelioid cells. The cells had ample cytoplasm, which had a brown to black (melanocytic) granular pigment compatible with a melanophoroma. To the best of the authors' knowledge, this is a unique description of a melanophoroma in P. olfersii.© 2023 American Society for Veterinary Clinical Pathology.