Pathological Spectrum of Melanoma: A Nine-Year Retrospective Analysis of Tumor Characteristics Across Diverse Anatomic Sites.

Melanoma is a highly aggressive malignancy originating from melanocytes, characterized by its potential to arise in various anatomic locations, both common and rare. The incidence of melanoma has been steadily increasing globally, with variations in clinical presentation, tumor behavior, and prognosis depending on the anatomical site involved. Understanding the diverse pathological spectrum of melanoma is critical for optimizing diagnostic and therapeutic strategies. This retrospective study provides a comprehensive analysis of melanoma tumor characteristics in 25 patients diagnosed and treated over a nine-year period at Meenakshi Mission Hospital. The study spans a wide spectrum of anatomical sites, including both typical cutaneous locations, such as the thigh and arm, and less common locations, such as the rectum, anal canal, esophagus, and glans penis. The patient cohort, predominantly male (92%, n=23), had a median age of 64 years (range 32-81 years). Tumor sizes varied from 1.2 cm to 5.1 cm, and ulceration was observed in all cases. Histologically, malignant melanoma was the most frequent diagnosis, with subtypes such as balloon cell melanoma, spindle cell melanoma, and superficial spreading melanoma also represented. Mitotic rates ranged from 5 to 22 mitoses per 10 high-power fields (HPF), reflecting varying levels of tumor aggressiveness. Lymphovascular invasion was noted in 12% of cases (n=3), highlighting the metastatic potential in some patients. This study underscores the pathological diversity of melanoma, highlighting the importance of thorough diagnostic evaluation and tailored therapeutic approaches. The findings contribute to a better understanding of melanoma's clinical and tumor characteristics across both typical and atypical anatomical sites, with implications for improving diagnostic accuracy and patient management.