Umbilical Basal Cell Carcinoma With Mixed Nodular-Morpheaform Features and Stalk Invasion: A Case Report and Literature Review.

Basal cell carcinoma (BCC) is a common cutaneous malignancy; however, its occurrence in the umbilicus is exceptionally rare, with only 22 cases reported to date, including the present case. We describe a 79-year-old man presenting with a 3.0 × 1.9 cm grayish-brown umbilical nodule with central ulceration. Histopathological examination revealed mixed nodular and morpheaform features, with tumor extension into the umbilical stalk. Given the anatomical complexity of the umbilical region, preoperative imaging may be suboptimal for accurately assessing deep tumor extension due to interference from pre-existing scar tissue. Therefore, thorough histopathological evaluation, including intraoperative frozen section analysis, is essential to ensure complete excision and optimal surgical management.