Acral myxoinflammatory fibroblastic sarcoma: Cytopathologic findings on fine-needle aspiration

Background: Acral myxoinflammatory fibroblastic sarcoma (AMFS) is a rare low-grade sarcoma with somewhat unique morphologic characteristics. While recurrences are relatively common, distant metastases are infrequent. Cytopathologic descriptions of AMFS are limited, prompting the current study. Methods: A retrospective review was performed at two tertiary-care hospitals, and 3 patients with this diagnosis were identified. The cytopathologic and clinical features were reviewed. The following clinical data was collected for each case: age, gender, site of lesion, treatment, and follow-up information. Results: Pertinent cytologic features included large atypical epithelioid cells with occasional macronucleoli and lipoblast-like features in a background of bland spindle cells, myxoid stroma, and inflammation. All patients presented with acral mass lesions. Metastatic disease to an inguinal lymph node was found in 1 patient. Conclusions: AMFS is a low-grade sarcoma which shows some characteristic cytologic features. However, due to the presence of occasional bizarre and pleomorphic giant cells, there can be overlap with higher-grade sarcomas, and correlation with histology, immunohistochemistry, and imaging are required to make this diagnosis.