Kimura disease

Definition: Kimura disease is a rare chronic inflammatory disorder of unknown etiology. It presents as a deep, subcutaneous mass in the head and neck region and is frequently associated with regional lymphadenopathy or salivary gland involvement.

The disease was first described in the Chinese literature as an "eosinophilic hyperplastic lymphogranuloma" but became widely known as Kimura disease after Kimura et al reported similar cases under the title on the unusual granulation combined with hyperplastic changes of lymphatic tissue.

Over the years, there has been considerable confusion between Kimura disease and angiolymphoid hyperplasia with eosinophilia (ALHE). Indeed, a number of early reports used the terms Kimura disease and ALHE synonymously. It is now thought, however, that the two diseases represent separate entities with distinctive clinic and histologic features.

Kimura disease is considered much more prevalent in young males of Asian lineage.

The nodular lesions are deep-seated in subcutaneous tissue and clinically may mimic a neoplasm. One of the important clinicopathologic features is its frequent association with regional lymph node and/or major salivary glands involvement. Indeed, isolated lymphadenopathy might be the only initial presentation of Kimura disease.

Kimura’s disease (eosinophilic lymphogranuloma), although previously included by some in this group of conditions, is a separate entity.

It is clinically different from HALE, typically presenting as large subcutaneous masses in young to middle-aged Asian men. It has been reported in non-Asians.Coexistence of the two conditions in the same patient suggests they may be part of a spectrum.

The majority of lesions are located around the ears or in the parotid gland. A case presenting with widespread prurigo nodularis-like lesions has been reported.

Elevated serum immunoglobulin E levels and peripheral blood eosinophilia are also common.

The etiology of Kimura’s disease is unknown but it may be an aberrant immune reaction to an as yet unknown stimulus.

Epstein–Barr virus DNA has been detected in lesional tissue in one case.

Clonal populations of T cells have been detected in some patients.

Clinical synopsis

 blood eosinophilia
 high concentration of IgE
 cervical lymphadenopathy

Microscopy

Kimura’s disease is composed of reactive lymphoid follicles with a dense infiltration of eosinophils, sometimes forming eosinophilic abscesses. An eosinophilic epithelioid granulomatous reaction with central eosinophilic abscesses has been reported. Mast cells are increased. Vessels (postcapillary venules) are increased in number, but their endothelial cells are usually flat.Vascular cords are unusual.

 eosinophilic epithelioid granulomatous reaction (12094384)
 multiple epithelioid granulomas with central eosinophilic abscesses and necrosis
 macrophages and giant cells phagocyte the apoptotic eosinophils at the edge of the granulomas
 follicular hyperplasia
 eosinophilic infiltrate
 proliferation of postcapillary venules

Treatment

Treatment includes surgical resection and regional or systemic corticosteroid therapy. Cytotoxic therapy, cyclosporine (ciclosporin), and radiation have also been used.

Prognosis

The disease has a good prognosis but it may recur locally. Death from Kimura’s disease is rare.

References

 Chen H, Thompson LD, Aguilera NS, Abbondanzo SL. Kimura disease: a clinicopathologic study of 21 cases. Am J Surg Pathol. 2004 Apr;28(4):505-13. PMID: 15087670