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A 16-year-old south Asian male presented with a four year history of right proptosis with a supero-anterior soft tissue mass and similar cheek swellings. The lesions have increased in size and the overlying skin is pruritic. He was otherwise healthy, but with a tendency towards atopy (allergies). There was no relevant family history, no recent travel history, and all routine vaccinations were up to date.

1.	What investigations would you perform for this patient?
	e -- (a), (b), and (c) Imaging in the form of MRI will help to see the extent of the soft tissue lesions. Full blood work up should be considered in all patients with orbital lesions; this patient was found to have an eosinophilia. At a minimum, a full blood count/differential, CRP, ESR and serum ACE should be taken. The lesions seen could be compatible with granulomatous lesions such as TB or sarcoid so a Mantoux test would be appropriate.
2.	Decision to do a biopsy would be based on the following findings:
	d -- (a) and (b) Anterior orbital biopsy and debulking are shown below.
3.	The tissue sample on histologic examination demonstrated an area of eosinophilic microabscess in a germinal center of a lymphoid nodule. This suggests a diagnosis of:
	b -- Kimura's disease A diagnosis of Kimura’s disease (KD) should be suspected based upon the chronic clinical history, clinical appearance, and the blood eosinophilia including: subcutaneous masses in head and neck region peripheral blood eosinophilia and elevated IgE characteristic histological findings The histology of lesions typically shows lymphoid follicles with germinal centre formation and eosinophilic infiltrates with associated foci of micro-abcesses. The other conditions listed all have other characteristic histological findings, but clinically the differential diagnosis should include all of these. A diagnosis of Kimura’s disease should prompt the attending ophthalmologist to check urinalysis for proteinuria, check immunoglobulin (Ig) levels, and consider long-term immunosuppression. Low power Medium power: germinal centre in lymphoid aggregate High power: eosinophil microabscess

This patient in fact had Kimura’s disease (KD) and remained undiagnosed for four years. KD is a rare inflammatory disorder of unknown cause which typically presents as subcutaneous nodules in the head and neck region of young Asian males. Although the disorder is well recognized and documented in Asia, it is less so in the Western world. Kimura’s disease was first described in Chinese in 1937 by Kim and Szetzo (as reported by Kung et al) as cases of eosinophilic granulomas of soft tissues.¹ The condition usually affects the subcutaneous tissues of the periauricular, parotid and submandibular regions. Orbital, eyelid and lacrimal involvement by KD is rare.² The clinical course of KD is thought to be benign and self-limiting, however, the condition may have systemic associations which require further investigation. Many patients with KD have a peripheral blood eosinophilia, and some may show elevated IgE titres as in this case.³ In addition, KD can be complicated by renal involvement, most commonly as nephrotic syndrome with proteinuria in 12-16% of cases.⁴ Orbital involvement remains rare. Clinically, the patients present with exophthalmos or palpable eyelid or orbital lesions, and often concurrent lymphadenopathy. Treatment consists of diagnostic biopsy and debulking of the mass which may be curative, however, recurrence is common.¹ This may be managed by further surgical excision and immunosuppressive agents such as systemic steroids and cyclosporin. To date, this patient has not had any orbital recurrence 24 months after excision biopsy.