Intro:
Zosteriform metastases of melanoma and other malignancies have been described previously. A study noted that zosteriform localisation more commonly occurs in the same region as the primary and that this distribution is associated with poor patient outcomes. The present case highlights an atypical presentation of malignant melanoma.
Methods:
We describe a patient with melanoma whose cutaneous distribution mimicked that of herpes zoster.
Findings:
An 86-year-old male was referred with concerns of a rapidly growing pigmented lesion on his back. The patient has a Fitzpatrick II skin type, lives in a high UV index environment, with several previous keratinocyte cancers but no personal or family history of melanoma. His past medical history includes hypertension and osteoarthritis. The patient denied any previous history of herpes zoster infection.
The patient reported a 4-week history of an enlarging pigmented skin lesion on his back. He denied pain or itch associated with the lesion. The patient denied any constitutional symptoms, including loss of appetite, weight loss, night sweats, or fevers.
The patient had a large, pigmented skin lesion on his back, with focal nodular components. Surrounding the larger area were several pigmented nodules, suspected to be in-transit metastases.
Histopathology confirmed malignant melanoma, with a Breslow thickness of at least 5mm with immunohistochemistry confirming KIT pK642E positive and BRAF negative. PET imaging noted a moderately avid right inguinal lymph node, which on core biopsy was confirmed as malignant melanoma. After multidisciplinary team discussions, he was deemed unsuitable for resection and referred to medical oncology for consideration of chemotherapeutic options.
Conclusion:
Our case highlights the significance of an atypical presentation of melanoma, emphasising the importance of a thorough assessment in all instances.