Palisaded myofibroblastoma. A benign XXXX of lymph node.

@entity808 @entity1 @entity2283 @entity5473 @entity5 @entity3 @entity361 @entity7085
We report 22 examples of an unusual and distinctive benign @entity361 arising exclusively from lymph nodes of the groin. The @entity5 , which presents clinically as a swelling, is composed of spindled cells arranged in solid sheets or short, vaguely palisaded fascicles similar to a @entity808 . The spindled cells blend gradually with large mats of eosinophilic material that appear as thick bands, @entity7085 , or circular profiles, depending on the plane of section. These eosinophilic structures, which represent a highly characteristic feature of the @entity5 , contain deeply eosinophilic, collagen-rich cores surrounded by a weakly eosinophilic, actin-rich cuff. The actin within these eosinophilic structures is derived by coalescence of intracellular actin globules extruded from neighboring cells. In all cases, a thin, compressed rim of normal lymph node was identified. Immunohistochemical analysis indicates that the cells express actin but lack S-100 protein, @entity5473 , @entity2283 , keratin, and epithelial membrane antigen. Delicate, linear striations were identified in only two cases by conventional histochemical techniques. The foregoing features suggest that the @entity5 is related to a myofibroblast or a specialized smooth-muscle cell. These @entity5 , therefore, probably arise from smooth-muscle-like cells, which are normally present in some lymph node capsules or stroma. Follow-up information on 17 @entity1 indicated that all are alive and well without any evidence of recurrence or @entity3 .
