Section shows multiple cores of fibrous tissue involved by a densely cellular inflammatory and fibroblastic/myofibroblastic process. The lesion is composed of fascicles and whorls of plump spindle to epithelioid cells with dense eosinophilic cytoplasm and oval, sometimes irregular nuclei, set in a collagenous to stroma showing prominent lymphoplasmacytic and histiocytic infiltrates, admixed with scattered neutrophils and occasional eosinophils. Foci show increased nuclear crowding and mild–moderate cytologic atypia, but atypical mitotic figures and tumor necrosis are not conspicuous in the examined levels. No evidence of salivary gland or lymph node architecture. Picture is suggestive of inflammatory myofibroblastic tumor (IMT). For confirmation, marker study (CK, Desmin, SMA, ALK, S-100, SOX10 and KI-67) is recommended.
Enlarged, necrotic lymph nodes in the left parotid and cervical regions.
Cores up to 1 cm long, with embedded.
Upper neck mass, core needle biopsy: