EP314 - Chronic Perianal Lesion: A Case Report of Extramammary Paget's Disease in a 55-Year-Old Male

Image or Table (Do Not add text here):

Purpose/Background: Extramammary Paget’s disease (EMPD) is a rare, slow-growing intraepithelial adenocarcinoma, primarily involving areas rich in apocrine glands, such as the genital, perineal, and perianal regions. The rarity of EMPD coupled with its often non-specific presentation poses significant challenges in clinical practice. Awareness of the clinical and histopathological features of EMPD is essential for timely diagnosis and appropriate treatment to prevent progression to invasive disease. We present a case of a 55-year-old Filipino male with a non-healing perianal lesion of one-year duration, diagnosed as EMPD. The patient experienced persistent pain during defecation and ambulation, rated as 2/10 on the pain scale. No other associated symptoms were reported.

Methods/Interventions: Initial examination revealed a solitary, erythematous lesion, approximately 4 cm by 3 cm, located in the right perianal region, which was firm, non-tender, and exhibited hyperpigmentation. Histopathological examination confirmed EMPD, demonstrating the presence of large cells with pale cytoplasm, large nuclei, and prominent nucleoli in the epidermis. Following the diagnosis, the patient was evaluated for the possibility of wide excision of the lesion. A magnetic resonance imaging (MRI) was performed to assess the extent of the lesion and to evaluate for any underlying malignancy which revealed no significant abnormalities. To further rule out the possibility of synchronous malignancy of the gastrointestinal tract, a colonoscopy was performed which demonstrated normal findings hence, excluding the presence of an associated colorectal carcinoma. The patient was treated with topical mupirocin and zinc oxide while awaiting surgical intervention. A bilateral v-y fasciocutaneous advancement flap on the perianal area was done, to ensure complete removal of the affected tissue while preserving the function and minimizing deformity of the perianal area.

Results/Outcomes: Patient was maintained in a lithotomy position and changed to prone position. V-shaped skin markings were made after measuring the perineal defect, with the apex sited at the greater trochanters and the limbs of the V reaching the superior and inferior ends of the perineal defect. Closure of the flap begins with approximating the edges of V by making vertical limb of “Y” or a “V-Y plasty”. This avoids tension along the midline and stabilizes the flap for closure. The midline was then closed by approximating the lateral edges of the bilateral de-epithelialized portion of the flaps. A separate drain for flap was not inserted because pelvic drain inserted through perineum was found to be sufficient to drain underneath of the flaps. Patient was kept in a lying down position till minimum 8 days to avoid shearing of the flap.

Conclusion/Discussion: EMPD of the perianal region is a rare, cutaneous adenocarcinoma that requires a high index of suspicion for early diagnosis. Histopathology and immunohistochemistry are essential in confirming the diagnosis and differentiating EMPD from other dermatoses. Surgical excision remains the primary treatment, but due to the high recurrence rates, close follow-up is critical. Novel treatment modalities, such as targeted therapy and immunotherapy, hold promise for patients with advanced or recurrent disease, highlighting the importance of continued research in this field.