• Lu Bofan, Xiu Xiaofei, Zhang Jingwen, Zhang Zuzhuo, Ma Tianxiao, Gao Feng, Zhang Guochuan, and Zhuang Zhou.
• Clinical medicine of Basic Medical College, HeBei Medical university, Shijiazhuang, Hebei, P. R. China.
• Medicine (Baltimore). 2023 Jun 23; 102 (25): e34034e34034.

RationaleMalignant melanoma (MM) is notorious for its remarkable morphological variation and aberrant histopathological patterns. In addition, Malignant Periopheral Nerve Sheath Tumor (MPNST) is an uncommon but aggressive soft tissue sarcoma. Because of the common embryological origin of melanocytes and Schwann cells in the neural crest, discriminating between a particular type of MM and MPNST can be difficult, particularly when they are amelanotic. Our goal is to increase awareness among clinicians of the rare variations of MM and the importance of medical history in improving the accuracy of the final clinical diagnosis.Patient ConcernsA 68-year-old man was admitted to the hospital due to pain in his right ankle, which had persisted for 8 months, along with swelling for 4 months. Medical history revealed delayed healing of right plantar for 5 years after a traumatic injury.DiagnosesThe ankle mass was initially diagnosed as MPNST through biopsy. After reviewing the patient's medical history and receiving the final pathological report following amputation, we have revised the diagnosis to metastatic amelanotic desmoplastic melanoma in the ankle part and lentigo maligna melanoma in the plantar part. This is due to both lesions displaying positive markers or mutated genes in immunohistology and Gene Mutation Detection, indicating homology between the 2 tumors.InterventionsDue to the malignant characteristics of the tumor and the patient's wishes, amputation of the right lower leg was carried out.OutcomesSubsequently, the patient was treated with interferon-γ and immunosuppressant PD-1 inhibitor, and survived for 1 year after amputation.LessonsClinical data, immunohistochemisty biomarkers and genes detection results can serve as valuable evidence for pathologists and clinicians in identifying the disease process. Collaborative efforts between clinicians and scientists are crucial in order to identify specific markers that can effectively differentiate between the 2 tumors, thereby enhancing the conclusiveness of the diagnosis.Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.

29 keywords...

hide…