Hepatic Endometrioma: A Rare Case of an Intraparenchymal Endometriosis of the Liver

Recognizing endometriosis as a differential diagnosis of hepatic cysts Case Presentation 34-year-old G4P4 woman with obesity, diabetes mellitus type II, oligomenorrhea, menorrhagia, and cholecystectomy presented with RUQ pain every 2-3 months for the past year. Pain became unremitting 2 days prior to admission. She had no recent travels including camping trips and no exposure to non-potable water. Physical exam was notable for well-nourished obese woman with RUQ abdominal tenderness without any rebound or guarding and negative Murphy's. Organomegaly, caput medusa, spider angiomata, asterixis, jaundice, and lymphadenopathy were not appreciated. Laboratory studies revealed elevated LFTs in a mixed pattern. MRCP showed a 8.6 cm complex multilocular cystic lesion with internal debris in the left hepatic lobe. Cyst was drained and fluid culture was negative. Other infectious studies including AFB, fungal stain, wet mount for strongyloides, and Fluorochrome stain for intestinal coccidia were negative. Cytology showed predominantly degenerated red blood cells with scattered neutrophils and macrophages with no malignancy After an ERCP with sphincterotomy, a diagnostic laparoscopy was performed. A large bulging cyst near the caudate lobe was drained and unroofed. Given lesion's proximity to hepatic artery, a complete excision was not done. Histo-pathology was suggestive of an endometriotic cyst. She was referred to ob-gyn who performed a total abdominal hysterectomy and bilateral salpingo-oophorectomy, which resolved her symptoms Discussion Hepatic endometriosis has been reported in the literature only in 22 other cases. One potential mechanism that has been postulated is retrograde menstruation causing transcoelomic spread and implantation. However, this usually results in dependent pelvic deposits rather than the intraparenchymal lesion seen here. Another potential mechanism for spread of endometrial tissue is via lymphatic or venous circulation. An interesting fact noted amongst these cases is a predilection for the left liver suggesting that endometrial tissue may travel around the falciform ligament and seed around it. Hepatic endometrioma is a rare condition and its etiology and pathogenesis are unclear. Given that no clinical or radiological features are specific to this condition, hepatic endometrioma should always be considered in the differential diagnosis of a woman presenting with a hepatic mass, with or without a history of pelvic endometriosis2387_A Figure 1. CT scan of hepatic lesion2387_B Figure 2. CT scan of hepatic lesion2387_C Figure 3. MRCP of hepatic lesion