Kimura's disease - An unusual presentation involving subcutaneous tissue, parotid gland and lymph node
A 22-year-old male patient presented to our dental clinics with bilateral facial swelling. The swelling on the left was larger, painful and appeared consequent to trauma 7 years prior to presentation. Initially small and diffuse, it progressively increased over time to its present size. The mass on the right had been present for a year and was asymptomatic. The patient did not report any increase in the size of the swelling at mealtime, reduction in salivary flow or pus discharge. There was no history of weight loss, low grade fever or night sweating. The dental history did not include any incidence of tooth-related pain or space infection. Medical, surgical and family histories were noncontributory. There were no symptoms suggestive of facial nerve involvement.\nPhysical examination revealed a 4 × 5 cm firm, nontender, subcutaneous mass in the region of the left parotid gland, overlying the left masseter muscle and extending from the zygomatic arch to the lower border of the mandible. The overlying skin was normal with respect to both color and temperature and facial nerve function was unaffected. The swelling on the right side had similar clinical characteristics but was 2 × 2.5 cm in size, located 3 cm from the corner of the mouth and well ahead of the anterior border of the ramus []. Bilateral submandibular and upper cervical lymph nodes were palpable. There was no axillary or inguinal lymphadenopathy and the liver and spleen were not enlarged.\nLaboratory studies revealed hemoglobin concentration of 155 g/L, white cell count 8 × 109/L and an absolute eosinophil count of 1.5 × 109/L (reference range: 0.0-0.4 × 109/L). The IgE serum level was not determined.\nA computed tomography (CT) scan disclosed enlarged superficial and deep lobes of the left parotid gland, a well-defined lesion measuring 3.3 × 2.4 cm in the right buccal space and enlarged level IB, level III and level V lymph nodes [Figures and ]. Fine needle aspiration cytology (FNAC) from the left parotid swelling and lymph nodes, as well as from the right cheek gave the impression of chronic nonspecific lymphadenitis and myoepithelial sialadenitis. Based on the CT and FNAC findings, an incisional biopsy from the right cheek swelling and image guided biopsy from the left parotid lesion was advised.\nHistopathological study of the specimen demonstrated lymphoid tissue with reactive follicular hyperplasia. Within the germinal centers, deposits of eosinophilic proteinaceous material and areas of folliculolysis were seen. The interfollicular infiltrate was rich in eosinophils with admixed lymphocytes and plasma cells. Numerous thin-walled vessels were present, often grouped in small foci; their endothelial lining was flattened with no epithelioid or vacuolated cells [].\nSurgical excision of the right subcutaneous mass and superficial parotidectomy for the left parotid swelling with selective neck dissection was performed. Postoperative recovery was good with no signs of facial nerve injury. However, after the patient was discharged from the hospital, he was lost to follow-up; hence presence or absence of recurrence could not be assessed.