**4.1 Clinical features**

Almost all patients with PEM are of reproductive ages and has a history of vaginal delivery. The perineal mass is often found in the episiotomy site or laceration site after vaginal delivery. Most patients have perineal cyclic pain corresponding to menstrual periods. Usually there is a mass between left labium majora and labium minora close to the clitoris. Perineal mass can be big and tender. Mostly the color of mass is normal. Sometimes the color of perineum is blue. Some patients have cyclic bleeding in perineal mass.

We analyzed 36 patients with perineal endometriosis who were operated on between 1983 and 2007 at Peking Union Medical College Hospital (PUMCH) retrospectively. The mean age of the 36 patients was 30.7 years (range, 23-44 years). Mean gravidity was 2.05 (range, 1- 6) and mean parity was 1.03 (range 1-2). The median latent period (time from delivery to the women having perineal pain or nodule) of these 36 cases was between 4 months and 13 years after delivery. All cases had cyclical perineal pain, which was progressive and correlated with their menstrual cycles (Zhu et al, 2009).

Diagnosis and Treatment of Perineal Endometriosis 57

revealing the involvement of anal sphincter. Preoperative endoanal ultrasonography, on the contrary, is a reliable technique for visualizing perianal endometriosis and for diagnosing anal sphincter involvement. The ultrasonographic features of the lesion are similar to those mentioned above. Its advantage over perineal ultrasonography is that it can reveal the involvement of anal sphincter clearly. Besides, endoanal ultrasonography can also help in the differential diagnosis of perianal lesions: ultrasonography of perianal abscess shows homogeneous hypoechoic lesions; ultrasonography of perianal fistula shows hypoechoic fistula passes through the longitudinal muscle tissues; ultrasonography of anal carcinoma and melanoma show solid lesions. As 16.7% of patients with PEM are concomitant with pelvic endometriosis, pelvic examination and pelvic ultrasonography should be taken to exclude pelvic endometriosis (Bacher et al., 1999; Toyonaga, 2006;

Fig. 2a,b. A 30-year-old woman with a mass in the right anterior perineal region adjacent to an episiotomy scar. Linear (a) and radial (b) ultrasound showed a heterogeneous mass containing cystic anechoic areas (black arrow) in the right anterior perianal region;the mass seemed to involve the external anal sphincter (white arrowhead) and not to involve the

Computer tomography (CT) also can be used in the diagnosis of perineal endometriosis by some authors. The value of CT however remains to be determined as it is both expensive and uses ionizing radiation. (Amato& Levitt, 1984). Fine needle aspiration cytology of the

internal anal sphincter (black arrowhead). (Toyonaga, 2006)

Watanabe et al., 2003).

(a)

(b)

## **4.2 Physical examination**

A thorough physical examination, which included a bimanual gynecologic examination, a trimanual gynecologic examination and a digital rectal examination (DRE), was performed on each case. The exam revealed a hard perineal nodule corresponded to the episiotomy scar or perineal laceration scar. In a patient with PEM and anal sphincter involvement, the nodule was also associated with part of the anal sphincter. In nearly half of all patients with PEM at PUMCH, the endometrioma eroded into the anal sphincter. Thus, it is imperative that further examination (including DRE and endoanal ultrasonography) should be used to confirm whether the anal sphincter is involved in a patient with PEM. Physical examination (including DRE) could provide extremely important additional clues. The mass is generally hard, frequently adjacent to an existing episiotomy scar or previous site of tearing or injury. For some patients, the skin color over the perineal lesions may be brownish on examination. Some may have cyclic ulceration or bleeding from the perineal mass.

Fig. 1. Preoperative status with firm nodule in the episiotomy scar (Odobasic et al., 2010)
