Jennings T A, Okby N T, Schroer K R, Wolf B C, Mihm M C
Department of Pathology and Laboratory Medicine, Albany Medical College, New York 12208, USA.
Histopathology. 1996 Aug;29(2):165-70. doi: 10.1046/j.1365-2559.1996.d01-497.x.
Desmoplastic malignant melanoma often arises in sun damaged skin of the head and neck and shows frequent neurotropism. Although metastatic melanoma frequently involve the parotid, direct spread to the parotid has been rarely reported. We evaluated five cases of desmoplastic malignant melanoma involving the parotid gland with clinical and pathological evidence of precursor cutaneous lesions in four of the five cases. The parotid involvement in four cases was tumoural, and three of these were not clinically suspected to be melanoma. The histological appearance in all five cases was that of a sarcomatoid tumour. Immunohistochemistry and electronmicroscopy performed on three of the cases showed only evidence of schwannian differentiation: the tumour cells were positive for S-100 protein and vimentin, and negative for cytokeratin and HMB-45. Electronmicroscopy showed no evidence of melanogenesis. All five tumours showed histological evidence of prominent neurotropism with one case demonstrating extension from overlying skin along cutaneous nerves to the superficial parotid. Thus, desmoplastic malignant melanoma may involve the parotid by neurotropic spread and can be pathologically indistinguishable from malignant schwannoma, a diagnosis which may be made erroneously in the absence of clinical information.
促纤维增生性恶性黑色素瘤常发生于头颈部受阳光损伤的皮肤，且常显示嗜神经性。虽然转移性黑色素瘤常累及腮腺，但直接蔓延至腮腺的情况鲜有报道。我们评估了5例累及腮腺的促纤维增生性恶性黑色素瘤病例，其中4例有临床及病理证据显示存在前驱性皮肤病变。4例腮腺受累表现为肿瘤性，其中3例临床未怀疑为黑色素瘤。所有5例的组织学表现均为肉瘤样肿瘤。对其中3例进行的免疫组化和电镜检查仅显示雪旺氏分化的证据：肿瘤细胞S-100蛋白和波形蛋白呈阳性，细胞角蛋白和HMB-45呈阴性。电镜检查未显示黑色素生成的证据。所有5个肿瘤均显示出明显嗜神经性的组织学证据，1例显示肿瘤从上覆皮肤沿皮神经延伸至腮腺浅叶。因此，促纤维增生性恶性黑色素瘤可能通过嗜神经蔓延累及腮腺，在病理上可能与恶性神经鞘瘤无法区分，若无临床信息，可能会误诊。
