Atypical lipoma as a potential pitfall in the cytodiagnosis of subcutaneous tumors. A report of two cases.

BACKGROUND

If well-differentiated liposarcomas of lipomalike type occur in the subcutis, they behave as benign neoplasms. For these tumors the term atypical lipoma was introduced in 1975. Fine needle aspiration (FNA) findings in these tumors may raise a false impression of malignancy.

CASES

Females aged 34 and 48 years presented with well-defined subcutaneous nodules in the left supraclavicular region and on top of the head, respectively. FNA showed fragments of mature fat tissue and numerous dispersed, large, hyperchromatic, often bizarre nuclei. Lipoma with atypical cells was diagnosed cytologically in one case and atypical lipoma in the other. Histologically both cases were evaluated as atypical lipoma.

CONCLUSION

A correct cytologic diagnosis of atypical lipoma can be established if cytomorphologic features are coupled with clinical data.