American Urological Association - Carcinoid Tumor (Monodermal Teratoma)
Carcinoid Tumor (Monodermal Teratoma)
- Carcinoid of the testis is considered a monodermal teratoma.
- 20% are associated with other teratomatous elements.
- In general occurs in older patients than GCT (10-83 years, mean 46).
- Carcinoid syndrome is rare, but when it occurs it predicts increased likelihood of metastatic disease.
- Serum AFP and HCG are normal; 5-HIAA elevated.
- Gross: solid well-circumscribed yellow-tan nodule; cystic component.
- Monotonous cells with abundant eosinophilic cytoplasm and characteristic "salt and pepper" chromatin (image A) & (image B).
- Growth pattern is nested, or may show a "ribbon and festooning" appearance.
- ITGCN rare in pure carcinoid.
- Immunohistochemistry: neuroendocrine markers synaptophysin+ and chromogranin+.
- DDX: primary testicular carcinoid (20% with teratomatous elements) vs. metastatic carcinoid (bilateral, microvascular invasion, and extratesticular involvement).
- Prognosis excellent with localized disease; excision is curative.