A Case of Amelanotic Malignant Melanoma of the Lingual Base That Was Diagnosed Based on a Biopsy of Late Metastasis to a Lumbar Vertebra after Being Misdiagnosed as HPV-Positive Oropharyngeal Anterior Wall Squamous Cell Carcinoma. (30th September 2021)

• Record Type: Journal Article
• Authors: Okuda, Takumi; Ide, Shinsuke; Kajihara, Kei; Tono, Tetsuya
• Other Names: Takano Kenichi Academic Editor.
• Is Part Of: Case reports in otolaryngology. Volume 2021(2021)
• Publication Date: 2021-09-30
• Subjects: Otolaryngology -- Periodicals; Otolaryngology -- Case studies -- Periodicals; Otolaryngology; Otorhinolaryngologic Diseases; Otolaryngology; Periodicals; Case studies; Periodicals; Case Reports; Fulltext; Internet Resources; Periodicals; 617.51
• DOI: 10.1155/2021/7139280
• Languages: English
• ISSNs: 2090-6765

Abstract

Abstract : We report a case of amelanotic malignant melanoma (AMM) in a 66-year-old female. AMM of the lingual base was diagnosed based on a biopsy of late metastasis to the bone marrow of the L4 lumbar vertebra. The patient was initially treated with chemoradiotherapy after being misdiagnosed with poorly differentiated human papillomavirus- (HPV-) related squamous cell carcinoma of the oropharyngeal anterior wall. p16 immunostaining is used to diagnose HPV-related oropharyngeal cancer. However, while p16 expression is used as a surrogate marker of HPV infection, it is important to be aware that p16 protein overexpression can also be caused by other factors. Malignant melanoma is known to express the p16 protein. Morphologically differentiating between AMM and poorly differentiated squamous cell carcinoma based on hematoxylin-eosin staining is difficult. Therefore, in cases that are pathologically diagnosed as p16-positive poorly differentiated oropharyngeal squamous cell carcinoma, it is important to rule out AMM.