Large Accessory Scrotal Spleen Masquerading as Testicular Tumor

A 75-year-old male presented with left scrotal swelling of 1 year’s duration. The firm, non-tender swelling was indistinct from the testis and consistent with left testicular tumor. Serum alpha fetoprotein, beta-human chorionic gonadotropin, and lactate dehydrogenase levels were normal. Scrotal ultrasonography and MRI showed 8.4x5.0x4.0cm mass in the left scrotum without calcification or necrosis (Figure 1A). The left testis could not be identified separately. A possibility of spermatocytic seminoma or lymphoma was considered. Left high inguinal orchidectomy was performed with uneventful recovery. At histopathology, the entire mass was noted to be an accessory spleen with adjoining atrophic compressed testicular tissue (Figures 1B,C,D).

Accessory splenic tissue is a common finding noted in 2% to 35% of individuals most often in and around the splenic hilum[1]. It can be classified as continuous or discontinuous with the spleen[2]. Accessory splenic tissue presenting as a scrotal mass is very rare[1]. Splenic tissue reaches the scrotum as a result of spleno-gonadal fusion, typically on the left side with tissue enveloped or adherent to the tunica albuginea[3].

This case is unusual because of the age of presentation, relatively short history, and large size of the mass. Most men present as young adults[2,3]. Surgery is unnecessary if the diagnosis can be made preoperatively[4]. Making a preoperative diagnosis to avoid surgery is practically difficult unless the patient can categorically state that the mass has been present and stable for years. In such a setting, Doppler imaging showing a hyper-vascular upper polar mass[1] confirmed by splenic scintigraphy using technitium-Tc99m[2] may help avoid surgery. Intraoperative frozen section histology might help avoid orchidectomy if exploration is deemed unavoidable[3,4]. The short history in our patient is difficult to explain. Patients with splenic disease such as leukemia or malaria may show concurrent increase in size of the accessory spleen[2]. However, our patient did not show any such disease.