Contributed by Sahr Syed, MD, Amir Ali Borhani, MD and Sheldon Bastacky, MDFINAL DIAGNOSIS
HIGH-GRADE EPITHELIAL STROMAL TUMOR OF THE LEFT SEMINAL VESICLE.
DISCUSSION
Primary malignant neoplasms of the seminal vesicles are rare. They include carcinomas, sarcomas, and tumors with mixed epithelial, and stromal components in descending order of frequency. Our patient's specimen was diagnosed as a primary high-grade epithelial stromal tumor of the left seminal vesicle with entrapped benign seminal vesicle glands, possibly arising from a primary seminal vesicle phyllodes tumor. This rare group of tumors is analogous to Phyllodes tumors which are known to arise in breast tissue and display a mixture of variably cellular stroma and glandular elements. Depending on the density and cytomorphology of the stroma, these tumors are classified on a continuum ranging from a fibroadenoma, low-grade phyllodes tumor, or high-grade phyllodes tumor (cystosarcoma phyllodes).
In the seminal vesicle, approximately 24 epithelial-stromal neoplasms have been reported which are analogous to phyllodes tumors in the breast and prostate which range from benign cystoadenoma and cystomyoma to malignant cystosarcoma (1-3).
These tumors are often picked up on digital rectal examination, but patients may also present with lower abdominal or perineal pain, bladder outlet obstruction, hematuria or hematospermia. The average patient age at presentation is 49 years (range, 31 to 70) and the tumors have been reported of sizes up to 16 cm in largest dimension (1). On gross examination, these neoplasms appear variably cystic and solid or multicystic and sponge-like (1).
On histologic examination, these tumors show biphasic morphology with both an epithelial and stromal component. There may also be a predominantly cystic component present, ranging from round to oval to even slit-like (1). Epithelial cells lining the cysts vary from cuboidal to columnar and flat, and may show focal hobnailing or tufting. The basal layer is usually intact (2). The tumor stroma shows a range of features with varying degrees of cellular density, pleomorphism and nuclear atypia. The management of these tumors has been variable and follow-up in most cases is short. However rare cases with lung metastases have been reported (2). However, given the overall rarity of the disease, continued surveillance is necessary until long-term outcomes are established (2).
REFERENCES
Contributed by Sahr Syed, MD, Amir Ali Borhani, MD and Sheldon Bastacky, MD
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