Introduction: Müllerian tumors are rare in males, with serous tumors representing the most often subtype with only 50 cases documented. Excluding the benign/ borderline counterparts, only 29 are reported as primary malignant testicular masses and only 4 are reported in the elderly. Due to rarity, there is no exact consensus in the optimal grouping and management of these patients. Herein we report a case of serous cystadenocarcinoma of the paratestis in an elderly Filipino male. Case Description: A 66 y/o male presented with scrotal enlargement. He had previously undergone a Hartmann’s procedure for fecal impaction. An incidental finding of a complicated hydrocele was noted on CT scan done few months prior his scheduled colostomy takedown. He was subsequently referred to urology service for evaluation. Tumor markers (AFP and βHCG) were all normal. One month prior to admission, a marked increase in the size of the right scrotum was observed, prompting decision to proceed with surgery. Discussion: Orchiectomy specimen evaluation requires careful assessment of tumor appearance, location, and extent. In this case, the tumor arises in the paratestis without involvement of the testicular parenchyma, showing solid and cystic areas with papillary excrescences. The tumor showed enlarged, hyperchromatic nuclei with irregular contours, abundant cytoplasm, and psammoma bodies. IHC revealed negative for calretinin, glypican3, CDX2, SATB2, and CK20, but positive for CK7, Pax8, ER, and WT1. Paratesticular serous cystadenocarcinoma diagnosis was made after carefully ruling-out mesothelioma, YST and/or metastases. P53 staining was equivocal, with 5% of cells positive amid broad negativity. Molecular testing was advised for grading and prognosis. Conclusion Serous cancers are rare in males and must require IHC for diagnosis and radical surgery due to high resistance to other treatments. Hydrocele being a frequent finding can sometimes delay the diagnosis. Careful monitoring remains critical for detecting progression and metastasis.
Cystadenocarcinoma, Serous ; Orchiectomy