Morphological and immunohistochemical characterization of an endometriotic cyst of the liver: diagnostic approach to endometriosis

Diagnosis, surgical treatment and postoperative outcomes of hepatic endometriosis: A systematic review

Endometriosis is characterized by the presence of endometrial-like tissue and stroma in extra-uterine locations. Hepatic endometriosis (HE) is one of the rarest forms of extrapelvic endometriosis. We aimed to summarize the existing evidence on HE with special consideration to natural history, diagnosis and surgical treatment. Three electronic databases were systematically searched for articles published up to March 2019. All appropriate observational studies and case reports addressing cases of women with HE were considered eligible for inclusion. A total of 27 studies which comprised 32 patients with HE were included. Mean age of patients was 39.7 years. Ten (62.5%) were nulliparous and 24 (75%) were women of reproductive age. Eleven patients (36.7%) had a history of pelvic endometriosis of various sites. Abdominal pain was the primary symptom in 28 patients (87.5%). Preoperative diagnosis of endometriosis was available for 5 patients and 6 underwent a preoperative diagnostic procedure. Cyst resection, minor and major liver resections were performed in 14/31, 9/31 and 8/31 patients, respectively. Preoperative diagnosis of HE is challenging due to variable radiologic features and clinical symptomatology. Nonetheless, it should be considered in the differential diagnosis of a liver mass especially in premenopausal women with a history of endometriosis. The type of resection of the endometriotic lesion is based on the extent and the location of the disease and presented with favourable outcomes concerning morbidity, symptom relief and recurrence.

Endometrial cysts within the liver: a rare entity and its differential diagnosis with mucinous cystic neoplasms of the liver

Endometrial cysts within the liver are rare but can present as diagnostic challenges on small biopsies or frozen sections and may mimic mucinous cystic neoplasms (MCN) of the liver. Five cases of endometrial cysts and 6 cases of MCNs within the liver were collected. The clinicopathological, imaging, and immunohistochemical features were systematically reviewed and compared. The average size of the endometrial cysts was 8.3 cm. Four patients had a prior pelvic operation and coexisting endometriosis at other sites. All 5 cases of endometrial cysts had positive ER staining within both the epithelium and the stroma. PR was also positive in both epithelial and stromal cells in 4 cases. Four cases had additional immunostains performed, which all showed cytokeratin 19 and cytokeratin 7 positivity (only in epithelium) and CD10 positivity (only in stroma). α-Inhibin and calretinin were negative for both the epithelium and the stroma in all 4 cases. All 6 MCN cases (mean size, 11.1 cm) had positive ER, PR, and α-inhibin staining only in the stroma. ER and PR were positive in both the epithelium and stromal cells in endometrial cysts, whereas they were positive only in the stromal cells of MCNs. The stromal cells were CD10 positive and α-inhibin negative in endometrial cysts as opposed to the opposite staining pattern in MCNs. Awareness of this distinct staining pattern and the possibility of endometrial cysts in the liver can lead to accurate diagnoses and appropriate treatment modalities.