Idiopathic Cervical Fibrosis—A New Member of IgG4-Related Sclerosing Diseases: Report of 4 Cases, 1 Complicated by Composite LymphomaCheuk, Wah MBBS*; Tam, Fiona K.Y. MBBS†; Chan, Alice N.H. MBBS†; Luk, Ivy S.C. MBBS‡; Yuen, Anthony P.W. MBBS‡; Chan, Wai-Kong MB, Bchir§; Hung, Terry C.W. MB, BChir§; Chan, John K.C. MBBS*The American Journal of Surgical Pathology: November 2010 - Volume 34 - Issue 11 - p 1678-1685 doi: 10.1097/PAS.0b013e3181f12c85 Original Articles Abstract Author InformationAuthors Article MetricsMetrics Idiopathic cervical fibrosis is a rare tumefactive inflammatory-sclerosing lesion involving the soft tissues of the head and neck, and a proportion of patients also have synchronous or metachronous inflammatory fibrosclerosing lesions in other anatomic sites. The latter finding suggests that this entity may represent a member of IgG4-related sclerosing diseases. We report 4 cases to support this postulation. The patients were male adults aged 42 to 89 years, who presented with an infiltrative, firm cervical mass. Two patients also had IgG4-related chronic sclerosing sialadenitis of submandibular gland and lymphadenopathy. Histologically, the cervical soft tissue lesions had ill-defined borders, consisting of coalescent nodular lymphoid aggregates accompanied by a sclerotic stroma. Nerve infiltration, skeletal muscle invasion, and phlebitis were present. There was a significant increase in IgG4+ plasma cells (87 to 327 per high-power field, with IgG4/IgG ratio of 63% to 98%). In the soft tissue lesion of 1 patient, there were expansile foci comprising dense sheets of plasma cells and small lymphoid cells that exhibited κ light chain restriction and clonal immunoglobulin gene rearrangement, consistent with supervening extranodal marginal zone lymphoma. The adjacent lymph node from the same patient showed Epstein-Barr virus (EBV)-positive classical Hodgkin lymphoma with typical morphology and immunophenotype (CD30+, CD15+, PAX5+). Thus lymphoma can supervene in the chronic inflammatory background similar to that recently documented for IgG4-related sclerosing disease of the ocular adnexa. *Queen Elizabeth Hospital †Kwong Wah Hospital ‡St. Paul's Hospital §Hong Kong Sanatorium, Hong Kong Correspondence: Dr Wah Cheuk, MBBS, Department of Pathology, Queen Elizabeth Hospital, Wylie Road, Kowloon, Hong Kong SAR China (e-mail: firstname.lastname@example.org). © 2010 Lippincott Williams & Wilkins, Inc.