Fine needle aspiration cytology of intranodal myofibroblastoma. A case report.
BACKGROUND
Intranodal myofibroblastoma is a rare, primitive, mesenchymal neoplasm of the lymph nodes first described in 1989. It behaves in a benign fashion and has a great predilection for the inguinal region.


METHODS
A 56-year-old man was referred for fine needle aspiration cytology of an inguinal lymph node. Smears were moderately cellular, with a predominant population of single, small spindle cells with no atypia. Most neoplastic cells were distributed as dissociated, single cells, with few groups. The cells showed metachromatic stromal material with a fibrillary quality. Nuclei were elongated, with pointed ends and occasional twisted forms. A remarkable finding on Papanicolaou-stained smears was hemosiderin granules. After a cytologic report of low grade spindle cell tumor, the node was excised, and a histologic and immunohistochemical diagnosis of intranodal myofibroblastoma was established.


CONCLUSIONS
Intranodal myofibroblastoma should always be considered when aspirating solitary inguinal lymph nodes. The presence of a low grade spindle cell pattern of variably dissociated cells with hemosiderin granules should lead to immunocytochemical studies. Muscle-specific actin expression in the absence of S-100 protein and vascular markers permits a more specific diagnosis.
Martínez-Onsurbe
Pilar
P
Department of Pathology, Hospital Príncipe de Asturias, University of Alcalá de Henares, Madrid, Spain.
Jiménez-Heffernan
José A
JA
Guadalix-Hidalgo
Gregorio
G
D001707:Biopsy, Needle; D006119:Groin; D006485:Hemosiderin / Q000032:analysis; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009379:Neoplasms, Muscle Tissue / Q000737:chemistry / Q000473:pathology*
D006485:Hemosiderin