Home Education AUAUniversity Education Products & Resources Pathology for Urologists Prostate Mesenchymal and Other Tumors Secondary Tumors

Secondary Tumors

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  • Includes neoplasms involving the prostate thru direct spread from adjacent organ or by metastasis from a distant site.
  • Mostly encountered as incidental autopsy findings and indicates late or widely disseminated stage of disease.
  • Seen in 5.6% of male autopsies with malignancies and 0.2% of prostate resections and biopsies.
  • Hematopoietic neoplasm is the most common secondary prostatic tumor.
  • Distant solid metastasis mostly originates from lungs (49%), skin (24%), and pancreaticobiliary (9%).
  • Direct tumor spread is predominantly from urinary bladder carcinoma (85%) and rectal adenocarcinoma (15%) (image A) & (image B).

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  • DDX of poorly differentiated prostate versus bladder urothelial and rectal cancers can be difficult in limited samples.
  • Immunohistochemistry may help in the differential diagnosis of primary versus secondary tumors of prostate (PSA- and PSAP-).
  • Rarely, GIST from the colorectal region may invade into prostate and even present as an intraprostatic mass mimicking a primary prostatic tumor.
  • GIST consists of spindle or fusiform cells arranged in ill-defined fascicles with characteristic perinuclear vacuolation (image C).
  • Immunohistochemistry: GIST is c-kit+ and DOG1+
  • DDX of GIST includes other spindle cell tumors of the prostate such as prostatic stromal tumors, leiomyosarcoma and inflammatory myofibroblastic tumor (all are c-kit-).