March 2021 — Hematopathology Case 1

The diagnosis in this case is: Kimura disease.

Correct answer: Kimura disease

Kimura disease is a chronic inflammatory disorder that involves subcutaneous tissues and lymph nodes predominantly in the head and neck region and is characterized by angiolymphoid proliferation and eosinophilia. Diffuse eosinophilia, eosinophilic microabscesses, and infiltration of germinal centers, sometimes resulting in folliculolysis, are part of the process. Vascular hyperplasia may be pronounced. Described in 1948, the disease is endemic in Asia an sporadic in the West. Kimura disease is suggestive of an infectious origin, but no pathogen has been demonstrated.

Incorrect: Hodgkin disease, mixed cellularity type

Has in common with Kimura disease eosinophils, plasma cells, and sclerosis, but lacks the hyperplastic germinal centers and deposits of IgE. The presence of Reed-Sternberg cells determines a positive diagnosis.

Incorrect: Angiolymphoid hyperplasia with eosinophilia (ALHE)

Owing to histologic similarities, ALHE has been confused with or mistaken for an early stage of Kimura disease. In contrast with Kimura disease, which is common in Asians, predominantly males, and seated deep in subcutaneous tissues, ALHE is seen in Caucasians, more often in females, involves the superficial skin forming clusters of papules, and is characterized by hypertrophic endothelial cells protruding into or occluding the vascular lumina. More important, the lymphadenopathy is an essential part of Kimura disease and is not present in ALHE.

Incorrect: Castleman disease

This entity includes vascular hyperplasia but lacks eosinophilia and has involuted hyalinized rather than hyperplastic germinal centers.

References

• Chen, Hong, et al. "Kimura disease: a clinicopathologic study of 21 cases." The American journal of surgical pathology 28.4 (2004): 505-513.
• Hui PK, Chan JK, Ng CS, Kung IT, Gwi E. Lymphadenopathy of Kimura's disease. The American journal of surgical pathology. 1989 Mar 1;13(3):177-86.
• Googe, P. B., N. L. Harris, and M. C. Mihm Jr. "Kimura's disease and angiolymphoid hyperplasia with eosinophilia: two distinct histopathological entities." Journal of cutaneous pathology 14.5 (1987): 263-271.