title: Rosai-Dorfman disease. Report of a case presenting as a midline thyroid mass.
abstract: To the best of our knowledge, this is the only reported case of isolated involvement by Rosai-Dorfman disease (RDD) of small, anterior cervical-midline lymph nodes, clinically presenting as a thyroid mass. Thyroid parenchymal involvement by RDD has been reported in only 3 cases in the literature. The present case shows involvement of RDD of a pretracheal and thyroid isthmic lymph node in a 38-year-old woman. The progressively enlarging, anterior neck mass was diagnosed as "lymph node" on a fine-needle aspiration biopsy specimen and subsequently interpreted to be an isthmic cyst on ultrasonography. A magnetic resonance imaging scan revealed foci of nodularity in the thyroid isthmus and pretracheal lymph node. Excisional biopsy of the 2 masses revealed typical features of sinus histiocytosis with massive lymphadenopathy in the lymph node. Review of the patient's previous fine-needle aspiration biopsy specimens also revealed the presence of similar features. Currently, the patient is well and has no other manifestation or recurrence of RDD.
authors.affiliation: Department of Pathology, Long Island Jewish Medical Center, Albert Einstein College of Medicine, New Hyde Park, NY 11040, USA.
authors.forename: Rubina S
authors.initials: RS
authors.lastname: Cocker
authors.forename: John
authors.initials: J
authors.lastname: Kang
authors.forename: Leonard B
authors.initials: LB
authors.lastname: Kahn
mesh_terms: D000328:Adult; D001707:Biopsy, Needle; D003560:Cysts / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D003949:Diagnostic Techniques, Surgical; D005260:Female; D015618:Histiocytosis, Sinus / Q000175:diagnosis* / Q000601:surgery; D006801:Humans; D008198:Lymph Nodes / Q000033:anatomy & histology; D013961:Thyroid Gland / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000473:pathology*; D014463:Ultrasonography