Anaplastic lymphoma kinase-positive anaplastic large cell lymphoma arising in a patient with hypersensitivity to mosquito bites.

Hypersensitivity to mosquito bites is defined as the appearance of intense skin reactive lesions and systemic symptoms subsequent to mosquito bites. Most cases of hypersensitivity to mosquito bites reported thus far have been associated with chronic Epstein-Barr virus infection or natural killer cell leukemia/lymphoma. In this study, we describe the case of an 18-year-old Korean boy who had hypersensitivity to mosquito bites associated with primary systemic anaplastic lymphoma kinase-positive anaplastic large cell lymphoma. After a mosquito bite, the patient developed a progressive cutaneous nodule on his left lower leg and regional lymphadenopathy in the left inguinal area. The histopathological and immunohistochemical findings suggested anaplastic lymphoma kinase-positive anaplastic large cell lymphoma. Positron emission tomography-computed tomography revealed increased fluorodeoxyglucose uptake in the left T4 vertebrae, left external iliac lymph nodes, left inguinal lymph nodes, and lateral subcutaneous region of the left lower leg. According to the clinical, histopathological, and immunohistochemical findings, as well as the imaging data, the patient was diagnosed with primary systemic anaplastic lymphoma kinase-positive anaplastic large cell lymphoma. Consequently, the patient received a total of 6 cycles of cyclophosphamide + doxorubicin + vincristine + prednisolone chemotherapy at 3-week intervals, after which the lesions regressed.