American Urological Association - Small Cell Carcinoma
Small Cell Carcinoma
- Rare, comprises 1% of all prostate cancer.
- May occur pure or mixed with acinar adenocarcinoma.
- ~1/2 of patients have history of acinar adenocarcinoma, and some with prior hormonal treatment.
- Neuroendocrine cells are devoid of androgen receptors; ADT may lead to clonal progression.
- Presents with rapid onset urinary tract obstruction, dysuria, nocturia, or urgency and some may present with paraneoplastic syndromes.
- Serum PSA level variable, may be normal.
- Indistinguishable from small cell carcinoma of other organs such as lung and bladder.
- Sheets of small round blue cells that infiltrate in a diffuse pattern (image A), (image B), (image C).
- Cells have nuclei with "salt and pepper" chromatin (dusty appearance with inconspicuous nucleoli).
- Crush artifact (smearing of cells) and nuclear molding is common.
- High mitotic activity, apoptosis and necrosis common.
- Immunohistochemistry: positive for neuroendocrine markers synaptophysin (image D) and chromogranin.
- Most patients present with EPE, large tumor, advanced stage, and distant metastasis.
- Poor prognosis with mean survival of <1 year after development of SCC component.
- No difference in prognosis between pure SCC and those SCC mixed with acinar adenocarcinoma.