What type of tumor is often diagnosed via cytology from a fluid-filled mass?

Choosing lipoma as the type of tumor often diagnosed via cytology from a fluid-filled mass is appropriate because lipomas are benign tumors composed of adipose (fat) tissue. When a lipoma becomes large enough, it can create a palpable fluid-filled mass that can be sampled using fine-needle aspiration (FNA) for cytological evaluation.

Cytology can help confirm the diagnosis of a lipoma by revealing a predominance of mature fat cells in the aspirate, indicating a benign nature. This method is particularly useful because lipomas typically do not arise from serous cavities, but when they develop in areas where they might influence adjacent structures, they can present as such masses, enabling the use of cytology as a diagnostic tool.

Adenomas, carcinomas, and lymphomas can also be diagnosed using cytology, but they are more frequently associated with solid masses or specific tissue types rather than fluid-filled masses arising from adipose tissue, which is a characteristic feature of lipomas.