Kimura Disease: A Clinicopathologic Study of 21 Cases.
American Journal of Surgical Pathology. 28(4):505-513, April 2004.Chen, Hong MD *; Thompson, Lester D. R MD +; Aguilera, Nadine S. Ives MD *; Abbondanzo, Susan L MD *
Kimura disease is a rare form of chronic inflammatory disorder involving subcutaneous tissue, predominantly in the head and neck region and frequently associated with regional lymphadenopathy and/or salivary gland involvement. This condition has a predilection for males of Asian descent and may clinically simulate a neoplasm. Kimura disease is sometimes confused with angiolymphoid hyperplasia with eosinophilia, which occurs in the superficial skin of the head and neck region. Although sporadic cases have been reported in non-Asians, there is no large, comprehensive study of Kimura disease in the United States. We report 21 cases with nodal involvement that, histologically, are consistent with Kimura disease. There were 18 males and 3 females (male/female ratio 6:1), 8 to 64 years of age (mean, 32 years), and included 7 Caucasians, 6 Blacks, 6 Asians, 1 Hispanic, and 1 Arabic. Anatomic sites of involvement included posterior auricular (n = 10), cervical (n = 6), inguinal (n = 3), and epitrochlear (n = 2) lymph nodes, with two patients having associated salivary gland involvement. Most (n = 16) cases had peripheral blood eosinophilia. Consistent histologic features were follicular hyperplasia, eosinophilic infiltrates, and proliferation of postcapillary venules.
Follow-up data on 18 patients revealed that 13 were alive without disease (3 had recurrence), mean follow-up, 10.9 years; 4 were alive with disease (2 had a recurrence), mean follow-up, 8.8 years; and 1 died with disease (12.7 years). Kimura disease has been described more often in Asians, but it does occur in non-Asians with a similar clinicopathologic presentation. It is a distinctive entity with no known etiology. Kimura disease has characteristic histologic features that are important to recognize and can be used to differentiate it from hypersensitivity and drug reactions and infections.
(C) 2004 Lippincott Williams & Wilkins, Inc.
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Kimura Disease - eMedicine
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Kimura disease (KD) was initially described in 1937, in the Chinese literature, by Kimm and Szeto1 as an “eosinophilic hyperplastic lymphogranuloma” and it became known as KD after its publication by Kimura et al.2 of similar cases in Japan under the title “Atypical granulation associated with hyperplastic abnormalities in the lymphoid tissue.” It is a chronic inflammatory disease involving the dermis and subcutaneous tissue characterized by one or multiple nodules or unpainful masses. It occurs predominantly as a unilateral manifestation in the head and neck and it is frequently associated with regional lymphadenopathy with or without involvement of salivary glands.3 Histopathologically, this condition is characterized by a lymphocytic inflammatory infiltrate, forming lymphoid follicles interspersed with aggregates of eosinophils and variable fibrosis in a richly vascular stroma. The pathophysiology of KD remains unknown, although allergic reaction, trauma and autoimmune process have been implicated as triggering factors.3,4
KD is a rare inflammatory disorder of unknown origin. Most of patients are male and oriental young adults. The prevalence in patients of other ethnicities is considered low. The disease is characterized by a triad of unpainful subcutaneous masses in the head and neck, eosinophilia in the peripheral blood and in tissues, and marked increase in serum levels of immunoglobulin E (IgE).16,17
At physical examination, patients with KD present one or more subcutaneous masses in the head and neck, accompanied by satellite adenomegalies and/or increased volume of salivary glands, especially the parotid and submaxillary glands (Figure 1). The lesions are firm at palpation, not painful and progressively increase in size with some of them reaching a diameter between 3 and 10 cm. There is a marked predominance of male patients; the male/female ratio is 2:1; and the onset of the disease occurs mostly in the third decade of life.18,19 Kung et al.3 studied 21 patients distributed as 18 men and 3 women, and they observed that the age of onset of lesions ranged from 7 to 50 years, with a mean age of 28 years. Such patients frequently reported pruritus in the overlying skin. In this study, most of the lesions were in the regions of head and neck; seven cases also presented involvement of the parotid gland. Lesions in other areas were also described such as the inguinal area, upper limbs and chest wall.3
Although KD pathogenesis remains unknown, it is considered nowadays an allergic disease and it seems to be a systemic immunological disorder. Eosinophilia and increased serum IgE levels make KD be considered a CD4(+) T helper 2 (Th2) allergic reaction. Th2 cells would produce interleukins (IL) IL-4, IL-5 and IL-13, which, in turn, would act in B cells favoring the production of antigen-specific IgE. Th2 cell proliferation and the overexpression of cytokines would play an essential role in the development of the disease.16,20
The histopathological changes in KD consist of a massive, nodular, diffuse and mixed inflammatory infiltrate composed mainly of lymphocytes and eosinophils, occupying all the extension of reticular dermis, subcutaneous tissue and, sometimes, the muscle fascia and the skeletal muscle (Figure 2). The inflammatory infiltrate is poorly circumscribed and contains numerous lymphoid follicles; infiltration of adjacent salivary glands may also occur.13,15 Lymphoid follicles are hyperplastic and contain prominent germination centers (Figure 3). Eosinophilic infiltration may occur occasionally with areas of necrosis (Figure 4). Although plasma cells and histiocytes are present, no epithelioid cells, multinucleated giant cells or granulomas are seen.3,10 Fibroplasia is seen in the subcutaneous tissue and around the lesion. Fibrosis can be sometimes observed as septa. Fibroplasia cellularity varies and tends to hyalinization of older lesions.13,21
The lesions are markedly of vascular type; capillaries are numerous and their endothelium is prominent and with no cytological atypias.13,21 Small arteries present hyperplasia or fibrosis of tunica intima and tunica muscularis. Large caliber arteries are rarely seen. Older lesions show more pronounced fibrosis, less active lymphoid follicles, less intense inflammatory infiltrate and a relatively less exuberant vascular component.13,15,21
Due to KD benign nature, treatment may range from observation and follow-up of mild and asymptomatic cases to conservative surgical excision, although lesions sometimes tend to recur. Other therapeutic options less commonly used include intralesional corticosteroids, cyclosporine, pentoxiphylline and radiotherapy.22-27An. Bras. Dermatol. vol.81 no.2 Rio de Janeiro Mar./Apr. 2006