Spectrum of Cutaneous Metastasis in Visceral and Haematolymphoid Malignancies: A Cross-sectional Study at a Tertiary Care Centre in Kolkata, West Bengal, India

Introduction: Cutaneous Metastasis (CM) is the spread of malignant cells from a primary site of malignancy to the skin. The incidence of CM ranges from 0.5% to 9% of all patients with cancer. CM may be the first sign of clinically silent visceral cancer or can even be a clue to tumour recurrence and heralds a poor prognosis requiring intense chemoradiotherapy. Aim: To study the spectrum of CM of internal malignancies, including haematolymphoid neoplasms. Materials and Methods: This cross-sectional study was conducted at Department of Pathology, Command Hospital Kolkata, West Bengal, India, over a period of two years from April 2020 to March 2022 and data was analysed over the next six months. A total of 16 patients who developed CM secondary to underlying solid organ or haematological malignancy were analysed. Categorical variables were summarised as percentages. Data in tables were presented as the frequency of variables (categories) or as absolute numbers. Results: The parameters studied included the primary site of malignancies, the frequency of various histological types at the primary site, and the common cutaneous metastatic regions. The mean patient age was 55.25 years (ranges 24- 72 years) with no gender predilection (M:F=1:1). The most common primary cancer site was the kidney and the oral cavity 4 each (25%), followed by breast, lung, and haematolymphoid malignancy, 2 each (12.5%), and 1 each of thyroid and gallbladder (6.25%). The most common site of CM was the head, abdomen, and epigastric wall 07/16 each (43.75%). The majority of the CM were identified as adenocarcinoma on histopathology. Conclusion: The CM occurs rarely and can be the initial presentation of an occult internal malignancy or may suggest recurrence if diagnosed later. Renal cell carcinomas and squamous cell carcinomas of the oral cavity are the tumours that have a high predisposition for CM, and hence these patients require close follow-up and surveillance.