Lymphangioma of the urogenital system is extremely rare and we present two cases treated at our institution over a one year period. The first case is a 3 year-old boy who presented with scrotal swelling and was initially thought to have a complex hydrocele. On surgical exploration, an extratesticular multiloculated cystic mass was discovered and testis-sparing excision of the mass was performed. Pathology revealed lymphangioma. The second case is a 5 year-old male who initially presented with

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... oss hematuria. Ultrasound was unremarkable but cystoscopy revealed varicosities extending from the bladder wall. On transurethral resection, histology showed non-specific benign vascular malformation. Magnetic resonance imaging (MRI) was obtained because of persistent hematuria and showed multiple bladder lesions suggestive of lymphatic malformation. Partial cystectomy was ultimately performed and histology confirmed lymphangioma. To the author's knowledge, this represents the fifth reported case of lymphangioma of bladder. Ó 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Lymphangioma is a benign lymphatic malformation, most commonly seen in the neck and axillary regions. Lymphangioma involving the urogenital system is extremely rare. Herein, we describe one case involving the bladder and another case involving the scrotum. Case report 1 A 3 year-old boy initially presented with a 1-year history of painless, progressive swelling in his left scrotum. Physical examination showed bilaterally descended testes and a non-tender, soft, compressible mass in the left hemiscrotum suggestive of hydrocele. Ultrasound of the testes was done and demonstrated fluid around the left testis containing low-level echoes due to debris and multiple septae (Fig. 1) . Based on clinico-radiological findings, a provisional diagnosis of complex left hydrocele was suggested. The swelling was initially explored via a left inguinal incision. A multicystic lesion separate from the left testis but densely adhered to the scrotal wall and perineum was identified (Fig. 2) . The left testis and spermatic cord were easily separated from the lesion. The left testis was normal in size and appearance. No hydrocele or hernia were identified. Complete excision of the lesion was performed and the overlying scrotal skin spared. Macroscopy showed tan to dark brown to black nodular tissue measuring 4 Â 3.8 Â 2.7 cm. Sectioning revealed multicystic compartments, some of which contained clear serous fluid, hemorrhagic dark brown material, and clear gelatinous material. Dilated cystic spaces were lined by bland endothelial cells, with small amounts of smooth muscle within the walls of vascular structures (Fig. 3) . Immunostaining was positive for CD31 and D2-30, consistent with a diagnosis of lymphangioma. At follow up 1 month later, there was no evidence of recurrence. Case report 2 A 5 year-old boy initially presented with penile pain and blood at the urethral meatus. Physical examination was unremarkable, urinalysis was negative, and a diagnosis of probable meatitis was given. The patient subsequently re-presented three years later at the age of 8 with intermittent gross hematuria. He had no additional complaints. Physical exam was again unremarkable. Urinalysis showed blood but was otherwise negative. Urine culture was negative for bacteria and ultrasonography showed no abnormalities. Cystoscopy under anesthesia was performed, which revealed a lesion with varicosities at the right lateral bladder wall (Fig. 4) . Bilateral retrograde pyelograms revealed no upper tract abnormalities. Transurethral resection of the bladder lesion was performed and histology revealed benign vascular malformation. The specimen showed submucosa with varying-sized vascular channels