The Umbilical Clue: Recognizing Sister Mary Joseph's Nodule

Sister Mary Joseph's nodule (SMJN) is a rare manifestation of intra-abdominal malignancy presenting as a metastatic umbilical lesion.

An 82-year-old woman with no prior medical history presented with a violaceous, ulcerated umbilical lesion. Imaging revealed peritoneal carcinomatosis, pelvic lymphadenopathy, and suspicious endometrial mass. Biopsies of both the cutaneous and endometrial lesions identified a serous endometrial adenocarcinoma with umbilical metastasis, confirmed by immunohistochemical markers (CK7+, PAX8+, CK20-, CDX2-). Given the extent of lymphatic and peritoneal spread, the patient was referred to palliative care.

SMJN accounts for approximately 10% of cutaneous metastases and often signifies advanced disease with a poor prognosis. Although rare, it may be the first visible sign of a hidden malignancy. This case highlights the importance of considering SMJN in differential diagnoses of umbilical lesions and underscores the need for prompt investigation to determine the underlying pathology. Early recognition can aid in appropriate management, although treatment is typically palliative due to the advanced stage at diagnosis.

Clinical significance: Sister Mary Joseph's nodule (SMJN) represents a rare but important clinical sign of metastatic intra-abdominal or pelvic malignancy, often indicating advanced disease.Clinical awareness: Heightened awareness of umbilical lesions among clinicians is essential, particularly in elderly patients presenting with nonspecific systemic symptoms such as weight loss, asthenia, or abdominal pain.Early diagnosis of SMJN is essential, as it frequently signifies advanced metastatic disease. Prompt recognition allows timely initiation of appropriate therapy or palliative care to optimize patient outcomes.