osteoncus

os·te·on·cus

(os'tē-ong'kŭs),
An osteoma, sometimes used with reference to any neoplasm of a bone.
[osteo- + G. onkos, bulk (swelling)]

osteoncus

An obsolete term for:
(1) Osteoma;  
(2) A benign or malignant, primary or metastatic bone tumour.