Fibrous pseudotumor of scrotum –A relatively lesser known entity causing great concern

Sir,

A 47-year old male presented to the Surgery outpatient department with an intrascrotal swelling which he discovered accidentally on self palpation. There was no other complaint but the patient was very apprehensive about the swelling. No history of trauma, previous surgery or any infection could be elicited. On palpation, the mass appeared to be a small, firm, non- tender nodule measuring 1.2 x 1x 0.5 cm near the epididymis and could be felt separately from the testis. On ultrasound, a mixed echoic nodular lesion measuring 10mm X 09 mm was noted in the right side of scrotum close to the lower pole of the right testis and appeared connected to the tunica. The right testis and right epididymis w ere reported normal. There was no associated hydrocele. The nodule was excised and sent for histopathological examination. There was no attachment to the tunica or epididymis. The specimen was an encapsulated, firm, white nodule measuring 1 cm in diameter. ([Figure 1]). On cut section, it was solid, white and appeared fibrotic. Histopathology revealed an encapsulated lesion showing densely hyalinized, plaque-like fibrous lesion with only scattered lymphocytes. ([Figure 2]). No calcification was noted. There was no mitosis or atypia. The tumor was positive for vimentin and SMA. A diagnosis of fibrous pseudotumor was rendered. The patient was asymp tomatic at 1month of follow-up.

Intrascrotal tumors are a source of great anxiety and concern as most of testicular tumors are malignancies. But tumors of paratesticular tissue, though uncommon, are rarely malignant. Fibrous pseudotumors are benign tumors presenting as scrotal masses and often create great clinicapathological confusion with malignancies. Although it is the second most common benign tumor of paratesticular region following adenomatoid tumor, only around 200 cases have been published in literature.^[1] Miyamoto et al reported a mean age of 42 years at presentation and also described three distinct hi stological variants: a) Plaque-like b) inflammatory sclerotic and c) myofibroblastic.^[2] As per this classification, the case described here was plaque-like as the lesion showed dense fibrosis without significant inflammation. Fibrous pseudotumors can present as solitary or multiple (sometimes numerous) discrete or confluent, mostly unilateral, hard nodules or rarely band-like thickening encasing the testis (fibromatosis periorchitis).^[3] The differential diagnosis include solitary fibrous tumor, leiomyoma, fibroma of tunica, neurofibroma, and idiopathic fibromatosis^[4] and meticulous examination of histopathology and relevant immunohistochmistry may aid in clinching the diagnosis. These lesions are ex tratesticular in location and may arise from tunica vaginalis, epididymis, spermatic cord or tunica albuginea. The exact cause of this benign fibro- inflammatory proliferative disorder is unknown; possible causes include prior trauma, infection, infarction etc or it may be idiopathic like our present case. Awareness of the lesion is very important to prevent unnecessary orchidectomy as surgical excision of fibrous tumors is curative in most of the uncomplicated cases. Imaging studies particularly Magnetic resonance imaging (MRI) studies are very helpful is ruling out testicular malignancies due to better delineation of extratesticular tissue by this modality.

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