Ultrasonography and Atypical Sites of Endometriosis

Abstract

In the present pictorial we show the ultrasonographic appearances of endometriosis in atypical sites. Scar endometriosis may present as a hypoechoic solid nodule with hyperechoic spots while umbilical endometriosis may appear as solid or partially cystic areas with ill-defined margins. In the case of endometriosis of the rectus muscle, ultrasonography usually demonstrates a heterogeneous hypoechogenic formation with indistinct edges. Inguinal endometriosis is quite variable in its ultrasonographic presentation showing a completely solid mass or a mixed solid and cystic mass. The typical ultrasonographic finding associated with perineal endometriosis is the presence of a solid lesion near to the episiotomy scar. Under ultrasonography, appendiceal endometriosis is characterized by a solid lesion in the wall of the small bowel, usually well defined. Superficial hepatic endometriosis is characterized by a small hypoechoic lesion interrupting the hepatic capsula, usually hyperechoic. Ultrasound endometriosis of the pancreas is characterized by a small hypoechoic lesion while endometriosis of the kidney is characterized by a hyperechoic small nodule. Diaphragmatic endometriosis showed typically small hypoechoic lesions. Only peripheral nerves can be investigated using ultrasound, with a typical solid appearance. In conclusion, ultrasonography seems to have a fundamental role in the majority of endometriosis cases in “atypical” sites, in all the cases where “typical” clinical findings are present.

Endometriosis of the Canal of Nuck: A Systematic Review of the Literature

“…A meticulous medical history from the patient with the groin mass suspected for endometriosis is critical for the preoperative diagnosis of the disease. In that setting, the patient should be thoroughly questioned about family history of endometriosis, history of any gynecological surgery with special consideration to previous caesarean section or myomectomy, and history of endometriosis and the respective treatment [ 50 ]. Patients with history of endometriosis are more likely to have concomitant disease of the inguinal canal through the round ligament.…”

“…Patients with history of endometriosis are more likely to have concomitant disease of the inguinal canal through the round ligament. Furthermore, the characteristics of pain including frequency, duration, association with menstruation and location should be also thoroughly asked [ 50 ]. Similarly, a proper preoperative imaging is also of critical importance.…”

Differential Diagnosis of Endometriosis by Ultrasound: A Rising Challenge

“…Uncommon locations of endometriosis are difficult to detect, and the accuracy of the ultrasound may be significantly reduced due to an inexperienced operator [ 62 ]. Endometriosis of the external genitalia (e.g., the perineum and mons pubis) may be easily confused with other conditions (i.e., abscesses, genital Crohn’s disease, skin trauma/swollen lesions, and hematomas) [ 63 , 64 ] because it may originate from abdominal wall lesions (i.e., muscular strains, heparin hematomas, muscular tumors, and hernias).…”

“…The rarest sites of endometriosis include lesions of the liver, pancreas, kidney, and gallbladder. Hepatic endometriosis appears as superficial hypoechoic lesions and may mimic an abscess, a hematoma, an angioma, or malignancy [ 62 ]. Endometriosis of pancreas, kidney, and gallbladder show hypoechoic lesions that can be seen by ultrasound and they require a second evaluation by computerized tomography or magnetic resonance imaging [ 62 ].…”

“…Hepatic endometriosis appears as superficial hypoechoic lesions and may mimic an abscess, a hematoma, an angioma, or malignancy [ 62 ]. Endometriosis of pancreas, kidney, and gallbladder show hypoechoic lesions that can be seen by ultrasound and they require a second evaluation by computerized tomography or magnetic resonance imaging [ 62 ]. These lesions do not present pathognomonic features that may differentiate endometriosis from malignancy or adenomas, so the definitive diagnosis relies on histology only [ 62 ].…”