The cells have finely granular chromatin and inconspicuous nucleoli. This mass is actually separated into three discrete tan, firm, focally hemorrhagic and calcified lobules, up to 8.5 cm in greatest dimension, separated by connective tissue and a small amount of fat. There are also occasional cystic spaces up to 0.2 cm containing serous fluid. Also receive was a portion of the enlarged ectopic parathyroid gland. Sections demonstrate an inflitrating tumor composed of lobules of round blue cells separated by bands of fibrous connective tissue.
Some cells also demonstrate nuclear folds and grooves.
The cells have a moderate amount of homogeneous eosinophilic cytoplasm and distinct cell borders. Mitotic figures are not prominent and necrosis is not a feature. The tumor shows vascular invasion and is extending outside of the capsule into the surrounding soft tissue. Anterior mediastinum, mediastinotomy - Thymic carcinoid , 11.0 cm in diameter. The ectopic parathyroid gland tissue shows a microscopic focus of carcinoid tumor.