A Unique Case of Diffuse Histiocytic Proliferations Mimicking Metastatic Clear Cell Carcinoma in the Hydrocele Sac
A 45-year-old man came with a complaint of scrotal swelling for 1 month and dull dragging pain for 7 days. He gave a history of minor trauma on the scrotum 15 days back. There was no other significant medical history. On local examination, the right hemiscrotum was tender (7 × 6 cm) and did not transilluminate. The left hemiscrotum (8.5 × 7cm) was nontender and transilluminated. There was no erythema or ulcer of the scrotal skin. There was no inguinal lymphadenopathy. Provisional clinical diagnosis of the right hemiscrotal mass with left hydrocele was made. Ultrasonography of the scrotum diagnosed right scrotal pyocele and left scrotal hydrocele. Both the testis and epididymis were normal. Left-sided Jaboulay repair and right scrotal incision and drainage was performed. Preoperative and postoperative intravenous antibiotics were given.\nPartially excised left hydrocele sac was received in multiple bits for histopathological examination []. Histopathological examination showed fibrocollagenous wall of hydrocele sac that was diffusely infiltrated by large cells having clear to multivacuolated cytoplasm []. Clear cells did not infiltrate outside the confines of the hydrocele sac wall. Nuclei were round to oval, showing moderate pleomorphism. Nuclei in few cells were pushed to the periphery with little distortion []. Scant mitotic activity was seen. Few small foci of hemorrhages and lymphocytes were seen. There was no necrosis, significant inflammation, epitheloid granulomas or giant cells. Metastasis of clear cell carcinoma was suspected.\nCytoplasm of the cells did not stain with Mucicarmin stain [Figure ]. In immunohistochemistry (IHC) staining, cells were negative with epithelial membrane antigen (EMA), pan-Cytokeratin and calretinin [Figure –]. Cells showed strong diffuse cytoplasmic positivity with CD68 []. Carcinoembryonic antigen (CEA) showed nonspecific staining [] and cytokeratin 7 (CK7), cytokeratin 20 (CK20) and prostate-specific antigen (PSA) were negative [–]. Absence of significant inflammation, epitheloid granulomas and Michaelis-Gutman bodies in the histology sections ruled out xanthogranulomatous inflammation and malakoplakia. A computed tomography scan of the abdomen and thorax ruled out primary neoplastic lesions in the thorax and abdomen. Final histological diagnosis of diffuse histiocytic proliferation (reactive) in the hydrocele was made.