Amyloid tumor: a clinical and cytomorphologic study.

We describe the cytologic findings and clinical presentation of three unusual cases of amyloid tumor. Two of our patients had low-grade lymphoid malignancies and the third insulin-dependent diabetes mellitus. In no cases was amyloid suspected as the cause of mass lesion. Two of our cases presented with superficial soft tissue mass and the third with right breast masses and bilateral axillary lymph node enlargement. Air-dried slides from all aspirated cases were stained with Diff-Quik for specimen adequacy evaluation. The remaining fixed slides were stained with Papanicolaou stain. Amyloid appeared as dark-blue to purple clumps of acellular material on Diff-Quik stain, accompanied with chronic inflammatory cell infiltrates and multinucleated giant cells, simulating granulomatous inflammation. Papanicolaou stain demonstrated cyanophilic to orangophilic acellular material. Amyloid was suspected and subsequently confirmed by Congo red stain.