Beyond the surface: The primary care diagnostic challenge of Sister Mary Joseph nodule

Sister Mary Joseph nodule is a rare manifestation of metastatic umbilical malignancy, most commonly associated with gastrointestinal and genitourinary cancers. It often signifies advanced disease and carries a poor prognosis. Early recognition is critical, yet diagnostic delays may occur due to nonspecific presentations in primary care. We report a case of a 63-year-old Malay woman with a history of diabetes mellitus, hypertension, and hyperlipidemia, presented with an 8-month history of progressive umbilical skin growth, mild abdominal discomfort, and constitutional symptoms, such as loss of weight and loss of appetite over two months. Retrospectively, she noticed an erythematous nodular skin lesion over the umbilicus, which had slowly increased in size over the last 8 months. She visited health clinics four times, where the lesion was treated as eczema, and she was prescribed steroid creams. However, her symptoms persisted. One month before referral, she developed significant weight loss, prompting her doctor to refer her to a dermatology clinic for suspected skin cancer. We aim to enhance clinical awareness among primary care providers about recognizing and promptly treating the disease to prevent further deterioration.