Rajendran Laavanya, Lim Chee Chean, Wee Chong Aun
Department of Otorhinolaryngology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603 Malaysia.
Indian J Otolaryngol Head Neck Surg. 2025 Jun;77(6):2401-2403. doi: 10.1007/s12070-025-05499-0. Epub 2025 Apr 28.
Amelanotic malignant melanoma is a rare subtype, comprising only approximately 2-8% of all malignant melanoma. Amelanotic melanoma of the parotid gland is even more scarce and difficult to diagnose thus causing a diagnosis dilemma when encountered. In this case report, we highlight the importance of consideration of diagnosis of amelanotic melanoma in parotid gland malignancies which will ensure prompt investigation and treatment. We further discuss the challenges in diagnosing amelanotic melanoma and relevant clinical examination and investigation.
We report a rare case of metastatic malignancy of parotid gland in a 74-year-old gentleman who presented with a parotid mass and overlying skin changes. Initial histopathology reports pointed towards sarcoma and lymphoma which caused a delay in diagnosis. However, a thorough examination and PET CT which revealed hypermetabolic peri and intra parotid lymph nodes prompted early surgical intervention of total parotidectomy. Special immunochemistry staining including vimentin, HMB45 and CD56 revealed metastatic amelanotic malignant melanoma of parotid gland. The patient then underwent adjuvant oncological treatment and recovered well.
Although rare, metastasis to the parotid gland from a primary amelanotic melanoma should be considered one of the differentials in parotid gland tumours, hence the proposed investigations for early detection, prompt diagnosis and treatment to ensure a better prognosis and quality of life.
无色素性恶性黑色素瘤是一种罕见的亚型，仅占所有恶性黑色素瘤的约2 - 8%。腮腺无色素性黑色素瘤更为罕见且难以诊断，因此遇到时会造成诊断困境。在本病例报告中，我们强调在腮腺恶性肿瘤中考虑无色素性黑色素瘤诊断的重要性，这将确保及时进行检查和治疗。我们还将讨论诊断无色素性黑色素瘤的挑战以及相关的临床检查和调查。
我们报告了一例罕见的74岁男性腮腺转移性恶性肿瘤病例，该患者出现腮腺肿块及覆盖皮肤改变。最初的组织病理学报告指向肉瘤和淋巴瘤导致诊断延迟。然而，全面检查及PET CT显示腮腺周围和腮腺内高代谢淋巴结，促使早期进行全腮腺切除术的手术干预。包括波形蛋白、HMB45和CD56在内的特殊免疫化学染色显示为腮腺转移性无色素性恶性黑色素瘤。患者随后接受了辅助肿瘤治疗，恢复良好。
尽管罕见，但原发性无色素性黑色素瘤转移至腮腺应被视为腮腺肿瘤的鉴别诊断之一，因此建议进行相关检查以早期发现、及时诊断和治疗，确保更好的预后和生活质量。
