Diagnosis of myiasis by fine needle aspiration cytology: a case report

Myiasis is the infestation of tissues and organs by dipteran larvae and is endemic in tropical areas. Diagnosis usually is made by demonstration of a larva or larvae in infected tissue, generally recognizable to the naked eye. In our case, diagnosis was based on fine needle aspiration cytology (FNAC).

A 59-year-old female patient with a painful neck mass was examined at an otorhinolaryngologic department after symptoms for several weeks. The lesion was found to be an absceding lymphadenitis, based on clinical symptoms, palpation and imaging (ultrasound and computed tomography). The lesion did not improve with repeated courses of antibiotics, so surgery was performed. Pus cultures collected after incision were negative, leaving origin of the inflammation undetermined. Smears from FNA of the residual mass demonstrated a worm-like pathogen alien to most European pathologists' experience. The pathogen was identified as a dipteran larva, leading to accurate etiologic diagnosis of myiasis. More scrupulous examination of the patient's history revealed she had spent her vacation in Australia, where she probably acquired the infection.

Our case demonstrates the growing importance of the pathology of infectious diseases. One reason for this may be the ever-increasing possibility, frequency and distance of travel.