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Bilateral orbital Kimura’s disease: A case report and brief review of literature

A 17‐year‐old male presented with complaints of gradually progressive painless swelling of both upper eyelids for the past 2 years [Fig. 1a]. There was no history of any trauma or other systemic illness. He gave a history of oral steroid intake 4 months back advised by a local practicing ophthalmologist, which led to complete remission of the swelling. However, it recurred within 2 weeks of stopping oral steroids.

A contrast-enhanced computerized tomography of head and orbit showed ill-defined lesions in both upper eyelids with moderate postcontrast enhancement [ Fig. 1b]. Lab investigations including anti-dsDNA, c3 complement, c4, c-ANCA, p-ANCA, ANA, serum ACE all were within normal limits. However, blood counts revealed absolute eosinophil count of 12 cells per microliter, erythrocyte sedimentation rate -9 mm/h, C-reactive protein -1.92, and a 1.67 serum IgG4 levels. Based on the clinical picture, differential diagnoses of Kimura's disease (KD), angiolymphoid hyperplasia with eosinophilia, IgG4 orbitopathy, and leukemic infiltrates were made.
The patient underwent an incisional biopsy. The histopathology revealed a tissue with proliferating capillaries and lymphatic channels infiltrated with lymphoid follicles and numerous eosinophils. These features were compatible with KD [ Fig. 1c]. The patient was prescribed oral corticosteroids and a remarkable reduction was noted by 3 weeks [Fig. 1d]. The patient has been on follow-up ever since and is doing well even after 6 months. The oral steroids have been slowly tapered.

Discussion
KD is a chronic inflammatory disorder of unknown etiology, which presents with tumor-like swellings and frequently affects young male adults in the Asian population. [1] It was first described in Chinese literature as "eosinophilic hyperplastic lymphogranuloma" by HT Kimm and C Szeto et al. in 1937. [2] The histological description was published by Kimura et al. [3] in 1948, and hence, the disease has borne his name. Wells and Whimster named the disease subcutaneous angiolymphoid hyperplasia with eosinophilia (ALHE) in 1969. [4] They had suggested that the two diseases were the same, subcutaneous ALHE representing any earlier stage which with time progressed to KD. [4] However, later studies divided the diseases into two separate categories based on histopathology findings.
It occurs commonly in the second to fourth decades of life (70-80%). [1] The clinical picture is usually painless, sometimes disfiguring subcutaneous nodules are present predominantly in the head-and-neck region. [1] This is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms. Although certain infectious etiologies have been postulated, KD is now believed to be related to an autoimmune or a delayed hypersensitivity reaction. An aberrant allergic response is further supported by the association with asthma, allergic rhinitis and conjunctivitis, atopic dermatitis, and peripheral hypereosinophilia, as well as raised serum IgE levels. [1] In 2018, Lee et al. [5] have reported a case of KD in a 30-year-old individual who also had a high-serum IgG4 level.
Most cases have been reported in the dermatology, oral surgery, and pathology literature. [6] It is usually a localized process without many systemic manifestations; however, few associated conditions have been reported, namely, nephrotic syndrome, asthma, tuberculosis, proteinuria, Loeffler syndrome, and even allergy to fungal infections like candida. [4] Regional lymph node involvement occurs in up to 75% of cases. [7] The disease rarely affects the ocular system. The first reported case with orbital involvement was by Nakai et al. [15] in 1966. [8] In the review of the literature we performed, we found a total of 49 cases of orbital KD [Supplementary Table 1]. The skin and lymph nodes of the postauricular and parotid gland region tend to be affected before the orbital involvement (superior orbit and lacrimal gland). [4] The condition is largely asymptomatic. [9] It may mimic nonspecific inflammations of the orbit, certain neoplasias, and even Graves' orbitopathy. In 2014, Li et al. [10] reported a 47-year-old Chinese male with orbital KD affecting the lacrimal gland mimicking IgG4 orbitopathy. At times, the disease may present with bilateral extraocular muscle enlargement, as documented by Gonçalves et al. in 2016. [11] In 2017, Francis et al. [12] have reported a recurrent KD limited to the inner canthus, which was not associated with any lymphadenopathy. At times, the disease may involve multiple structures in the orbital along with regional lymph nodes, as described by Chakraborti et al. in 2019. [13] Computed tomography scan findings are nonspecific and consist of homogeneously enhancing lesions. On MRI studies, KD usually presents hypointense areas on T1 and varying intensity on T2 weighted and postcontrast images. [14] A proliferation of lymphoid follicles, dense fibrosis, capillary proliferation, and germinal centers are typically noted on histopathological examination, showing interfollicular infiltration by eosinophils.
The treatment modalities for KD include observation, surgical excision, oral corticosteroid, cytotoxic drugs, and radiation therapy or any combination. [8] Corticosteroids remain the primary medical therapy. However, the disease mostly recurs once the steroid is weaned off where surgical excision then can be performed. In our case, the patient was explained regarding all the treatment options and started on oral corticosteroid 0.5 mg/kg. There has been a marked reduction in the swelling, and the patient has been on follow-up.

Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest
There are no conflicts of interest.