Recurrent Neurocysticercosis: Not So Rare

Solitary cysticercus granuloma (SCG) appearing as a single ring-enhancing lesion (SREL) is the most frequently encountered imaging finding in patients of neurocysticercosis (NCC) in India and during follow-up, most of SCGs resolve with or without calcifications. Recurrent SCG have been rarely reported.

The aim of our study is to report the incidence of recurrent SCG in a cohort of patients with SCG and postulate the hypothesis.

This retrospective study included 278 patients with SCG meeting the criteria of NCC. Their medical records and imaging studies were analyzed.

Out of 278 patients, 119 patients with SCG meeting the criteria of NCC with follow-up imaging were included. 15 (12.61%) had recurrent NCC and 104 (87.4%) patients did not have any recurrence during a median follow-up of 14.23 months (range; 0.24 - 113.3) and 25.26 months (range; 3.09- 98.11) respectively. Out of 15 recurrent NCC cases, ten patients had documented imaging resolution or partial regression of previous lesion followed by occurrence of new SCG in the same location, three patients had change in morphology of lesion from solitary discrete REL to solitary conglomerate REL secondary to development of new cysticercus granuloma adjacent to old lesion patients had recurrent lesions adjacent to previous lesion and two patients had new SCG in different locations following regression of old SCGs.

Recurrent SCGs are not uncommon in NCC and recurrence is more likely to occur at the site of initial infection and therefore may be mistaken for persistent infection or other granulomatous lesions.