Umbilical granuloma mimicking Sister Mary Joseph's nodule.

What is known about this subject in regard to women and their families? Sister Mary Joseph’s nodule is an umbilical metastasis that may indicate an underlying or recurrent malignancy and therefore requires prompt evaluation. Although umbilical granulomas are common in neonates, they are rare in adults and may be difficult to distinguish clinically from malignant umbilical lesions. What is new from this article as messages for women and their families? Adult-onset umbilical granuloma can mimic Sister Mary Joseph’s nodule, even in a cancer survivor without a history of abdominal surgery, piercing, or trauma. Benign causes should remain in the differential diagnosis of a new umbilical mass in cancer survivors, and biopsy combined with appropriate systemic evaluation can help establish the diagnosis and avoid diagnostic delay. Dear Editors, Sister Mary Joseph’s nodule (SMJN) is an umbilical metastasis typically arising from gastrointestinal and gynecologic malignancies. New umbilical nodules in cancer survivors may indicate SMJN and require prompt evaluation. We report an adult-onset umbilical granuloma whose clinical and imaging features mimicked SMJN. A 55-year-old postmenopausal Japanese woman with a history of stage I breast cancer treated by breast-conserving surgery 7 years earlier was referred for evaluation of an umbilical mass noted 3 weeks earlier (Fig. 1A). She had no history of abdominal surgery, piercing, or trauma. The mass was a tender, firm, poorly mobile 2-cm umbilical nodule with brownish discharge and no surrounding skin color changes. Because the lesion was located within the umbilical cleft, visualization of its surface and margins was limited. Laboratory tests were unremarkable. Ultrasonography showed a round hypoechoic structure at the site of the mass (Fig. 1B). Contrast-enhanced computed tomography demonstrated a 1.7-cm enhancing umbilical mass, a 1.1-cm hepatic nodule in S8, and enlarged celiac-axis and left-axillary lymph nodes. Given her prior breast cancer and computed tomography results, malignancy probability was heightened. Subsequently, esophagogastroduodenoscopy, colonoscopy, gadoxetic acid–enhanced magnetic resonance imaging, and positron emission tomography–computed tomography were performed. Esophagogastroduodenoscopy and colonoscopy were normal; gadoxetic acid–enhanced magnetic resonance imaging confirmed the hepatic lesion as a hemangioma. Positron emission tomography–computed tomography showed abnormal uptake in the umbilical area but no other findings (Fig. 2A). A biopsy was performed for diagnosis. Histopathological examination showed partial disruption and ulceration of the epidermis with extensive necrotic tissue beneath. Granulomas surrounded the necrotic areas, suggesting umbilical granuloma, tuberculosis, or other granulomatous infections (Fig. 2B). Interferon-gamma release assay was negative, and extrapulmonary tuberculosis was considered unlikely. Fungal and Ziehl–Neelsen staining were also negative. These findings supported a diagnosis of umbilical granuloma. Given the potential risk of umbilical deformity, surgical excision was deferred, and follow-up observation was chosen. At the 3-month follow-up, the mass showed no significant change in size, but the tenderness had improved. Umbilical granulomas are typically observed in neonates, but are rare in adults. A few adult cases have been linked to urachal remnants. Other potential causes include a history of abdominal surgery, piercing, or trauma. None of these were present in this patient’s history. Although adult umbilical granulomas exist in the literature, few cases have been documented in cancer survivors, complicating diagnosis. Given the clinical information, SMJN was considered a leading diagnosis. It occurs in patients with abdominopelvic malignancies and is associated with a poor prognosis, with a median survival time of 7.9 months. SMJN typically presents as a firm mass ranging from 0.5 to 10 cm, which was consistent with our patient’s presentation. Other differential diagnoses include cutaneous endometriosis, sarcoidosis, and dermatofibroma, but these diagnoses were inconsistent with the exam results. This is a rare case of an adult-onset umbilical granuloma mimicking SMJN in a cancer survivor. In such patients, cancer metastasis, known as SMJN, is often the critical consideration. Recognition of benign mimics of SMJN facilitates simultaneous biopsy and whole-body evaluation, streamlining workup and preventing diagnostic delay. Conflicts of interest None. Funding None. Study approval N/A Author contributions TK and MS: Participated in conceptualization and investigation, and contributed to writing the original draft. YT and YM: Participated in reviewing and editing the draft. KA and TH: Participated in data curation, and contributed to reviewing and editing the draft. GD and TN: Participated in validation. Patient consent Informed, written consent was received from all patients for whom photographs are present in the manuscript. References 1 Iijima S. Umbilical granuloma: frequency, associated factors, 10-year treatment trends, and effectiveness at a single hospital in Japan. J Clin Med 2023;12:6104.2 Ekwueme KC, Parr NJ. Infected urachal cyst in an adult: a case report and review of the literature. Cases J 2009;2:6422.3 Hugen N, Kanne H, Simmer F, et al. Umbilical metastases: real-world data shows abysmal outcome. Int J Cancer 2021;149:1266–73.4 Gabriele R, Borghese M, Conte M, Basso L. Sister Mary Joseph’s nodule as a first sign of cancer of the cecum: report of a case. Dis Colon Rectum 2004;47:115–7.5 Żółkiewicz J, Sławińska M, Maińska U, Nowicki RJ, Sobjanek M, Thomas L. Dermoscopy of umbilical lesions-a systematic review. J Clin Med 2024;13:1790.