Primary umbilical endometriosis: a cause of a painful umbilical nodule

Abstract

A female patient presented with a painful swelling in the umbilicus. Ultrasonography demonstrated a hypodense nodule of 1.8 cm. Surgical exploration revealed a subcutaneous, dark discoloured, lobulated swelling at the bottom of the umbilicus, which turned out to be primary umbilical endometriosis (PUE). Primary umbilical endometriosis is a rare and benign disorder, caused by the presence of ectopic endometrial tissue in the umbilicus, which can present as a painful, discoloured swelling in the umbilicus. The clinical distinction between primary umbilical endometrioses and other causes of an umbilical nodule is difficult. Additional imaging modalities do not show any pathognomonic signs for establishing this diagnose. Surgical exploration and excision are a safe and definitive treatment of primary umbilical endometrioses. This case highlights the importance of including PUE in the differential diagnosis of women with a painful umbilical nodule.

Primary umbilical endometriosis: Menstruating from the umbilicus

“…Sometimes we can also use ultrasound imaging, CT scan or magnetic resonance imaging (MRI) to study the depth and the extent of the mass and if the mass is cystic or solid. However, CT scan and MRI are of little value in diagnosing intra-abdominal endometriosis [17][18][19] . In patients operated on for umbilical endometriosis, laparoscopic exploration has been advocated in order to exclude possible further foci of intra-abdominal endometriosis, since pelvic endometriosis cannot be definitively excluded on transvaginal ultrasound or clinical examination.…”

Primary umbilical endometriosis successfully treated with dienogest

“…A majority of umbilical endometriosis occur in patients with a history of surgery, such as laparoscopy. Laparoscopic surgery may cause iatrogenic dissemination and subsequent implantation of endometrial tissue at the skin [5]. The uniqueness of this case lies in the fact that the umbilical endometriosis occurred in a patient without any previous surgery, and hence classified as a PUE.…”

“…Interestingly, it frequently occurs as a solitary nodule without concomitant pelvic endometriosis [8]. An umbilical nodule presents a wide differential diagnosis, including abscess, hernia, infection, granuloma, sebaceous cyst, benign and malignant skin tumour, and adenocarcinoma [5]. Classical presentation of a discrete blackish-purple nodule in the region of the umbilicus with cyclical bleeding is strongly suggestive of umbilical endometriosis.…”

Umbilical endometriosis: a potential encounter for general surgeons

“…Previous authors have reported some difficulty in diagnosing primary UE; the sensitivity and specificity of ultrasonography, computerized tomography and magnetic resonance imaging are low and no techniques describe pathognomonic findings . In this patient's case, imaging assisted in providing information regarding the size of the nodule and exclusion of hernia.…”