The suffix [-oma] means "tumor", "mass", or "growth". It should be noted that the word [tumor] is originally Latin, and means "swelling" or "bulging". Sometimes the plural form [-omata] can be used.
It is a general misconception that the suffix [-oma] or the term [tumor] are synonymous with "cancer". This is not so. [Tumor] only means a mass and the type of mass, benign or malignant is not implied in the term. A cancerous mass will be denoted by the addition of the root term [-carcin-] meaning "cancer" therefore the combined root and suffix will be [-carcinoma]. There are other root-suffix combinations that also mean "cancerous".
The suffix [-oma] can be found in many medical words, such as:
• Hematoma: from the Greek root [-hem-] meaning "blood". A mass of blood