Specimen fine-needle aspiration cytology of littoral cell angioma with histologic and immunohistochemical confirmation.

We performed a specimen fine-needle aspiration biopsy (FNAB) of a littoral cell angioma (LCA) from a 33-yr-old male who underwent elective splenectomy due to thrombocytopenia secondary to Wiscott-Aldrich syndrome. Gross examination revealed a 420-g, diffusely enlarged spleen which contained two moderately well-circumscribed, soft brown lesions measuring 0.3 and 1.0 cm, respectively. Benchtop aspiration of the lesions following splenectomy yielded a cellular sample composed predominantly of dispersed single cells, which ranged from columnar to spindle to circariform in shape. Nuclei were round to oval with even chromatin, and many contained single longitudinal grooves. A majority of the cells contained abundant, granular hemosiderin pigment, a key cytologic feature. Immunohistochemical staining revealed reactivity for antibodies to CD68 and factor VIII-related antigen with no reactivity for S-100 protein and CD8. Littoral cell angioma must be differentiated from splenic hamartoma, hemangioma, angiosarcoma, littoral cell angiosarcoma, and epithelioid and spindle cell hemangioendothelioma. A combination of cytologic features and immunohistochemical results should enable an accurate diagnosis. Copyright 2000 Wiley-Liss, Inc.