Mullaney Lisa C, Rigas Johanna, Watson Christine, Puttaswamy Anil, Haviland Lisa, Molitor Laure, LaDouceur Elise E B
1The Joint Pathology Center, Silver Spring, Maryland; and.
2Altasciences Preclinical, Everett, Washington.
J Am Assoc Lab Anim Sci. 2025 Jan 1;64(1):44-48. doi: 10.30802/AALAS-JAALAS-24-057.
There are few reports describing spontaneous neoplasms in cynomolgus macaques, despite the frequent use of this species in laboratory research. This report describes cytologic, histologic, and immunohistochemical findings of a cutaneous to subcutaneous nerve sheath tumor located within the haired skin of the abdomen of a 2.5-y-old, intact, female, captive Mauritius cynomolgus macaque. The nerve sheath tumor was well demarcated, partially encapsulated, densely cellular, and extended from the subcutis to the most superficial dermis, abutting the epidermis. Neoplastic cells formed intersecting streams and had a high mitotic count (18 per 2.37 mm2). Due to the substantial morphologic overlap of this neoplasm with amelanotic melanoma, particularly the close association with the epidermis, immunohistochemistry was required for definitive diagnosis. Neoplastic cells were immunoreactive to vimentin, S-100, SOX10, laminin, collagen IV, and CD56, and negative for melan-A, tyrosinase, MITF, and HMB45. This immunohistochemical profile is diagnostic for nerve sheath tumor based on human and canine criteria and rules out amelanotic melanoma. Despite incomplete excision, the nerve sheath tumor had not grossly recurred after 1 mo, at which point the animal was euthanized for unrelated reasons. This report underscores the importance of using an immunohistochemical panel in cases of cutaneous and subcutaneous spindle cell neoplasms, as there is substantial morphologic and immunohistochemical overlap between nerve sheath tumors and melanocytic neoplasms due to their shared neuroectodermal origin. To our knowledge, this is the first report of a nerve sheath tumor in a cynomolgus macaque, and one of the few reports of spontaneous neoplasia in this species.
尽管食蟹猴在实验室研究中被频繁使用，但关于其自发性肿瘤的报道却很少。本报告描述了一只2.5岁、未育、雌性、圈养的毛里求斯食蟹猴腹部有毛皮肤内的皮肤至皮下神经鞘瘤的细胞学、组织学和免疫组化结果。神经鞘瘤边界清晰，部分被膜包裹，细胞密集，从皮下组织延伸至最浅表的真皮层，紧邻表皮。肿瘤细胞形成交叉束状结构，有较高的有丝分裂计数（每2.37平方毫米18个）。由于该肿瘤在形态上与无色素性黑色素瘤有很大重叠，特别是与表皮关系密切，因此需要免疫组化来明确诊断。肿瘤细胞对波形蛋白、S-100、SOX10、层粘连蛋白、IV型胶原和CD56呈免疫反应，而对黑色素A、酪氨酸酶、小眼畸形相关转录因子（MITF）和HMB45呈阴性。根据人和犬的标准，这种免疫组化特征可诊断为神经鞘瘤，并排除无色素性黑色素瘤。尽管切除不完全，但神经鞘瘤在1个月后未出现肉眼可见的复发，此时该动物因无关原因被安乐死。本报告强调了在皮肤和皮下梭形细胞瘤病例中使用免疫组化组合的重要性，因为神经鞘瘤和黑素细胞性肿瘤由于其共同的神经外胚层起源，在形态学和免疫组化上有很大重叠。据我们所知，这是食蟹猴神经鞘瘤的首例报告，也是该物种自发性肿瘤的少数报告之一。
