Inguinal Dermoid Cyst Associated With Ipsilateral Undescended Testis in an Adolescent Male: A Case Report

ABSTRACT Groin swellings are the most frequent presenting clinical signs, which most frequently arise due to an inguinal hernia or lymphadenopathy. There are also rare congenital lesions, such as dermoid cysts, which can present similarly to common lesions, also leading to a diagnostic challenge. Inguinal dermoid cysts, particularly those that present with an undescended testis, are extremely rare, and there are sparse reported cases. An 18‐year‐old male patient presented with painful, slowly increasing swelling in the left inguinal canal for 3 months. On physical examination, a firm, non‐reducible, tender mass and empty left hemiscrotum were noted. Ultrasonogram revealed a heterogeneous hypoechoic mass containing echogenic foci for hair or calcification, and no presence of the left testis within the scrotum. Tumor markers were within normal limits. At opening, inguinal exploration, a well‐defined cystic mass with thick sebaceous material and hair was excised, and orchiopexy of the viable undescended testis was performed. Histopathology showed a dermoid cyst with stratified squamous epithelium, sebaceous glands, and hair follicles. The postoperative course was uneventful with no recurrence on 4‐month follow‐up. Inguinal dermoid cysts are rare developmental cysts that are also seen as lipomas or hernias. Their association with undescended testes makes them even more challenging to diagnose. Ultrasonography is the preferred imaging before surgery, and surgical resection is the preferred management to prevent recurrence. This case illustrates the importance of dermoid cysts in the differential diagnosis of inguinal masses, particularly in this patient with cryptorchidism, and highlights the importance of surgical exploration and histopathological diagnosis in management.