A rare suspected case of chronic nodular granulomatous herpes simplex encephalitis in an adult

Abstract

Herpes simplex encephalitis is the most common sporadic viral encephalitis in the western world, HSV-1 (herpes simplex virus) being the mostly commonly implicated serotype. The disease is usually monophasic, although patients may relapse weeks, months or years after initial infection. This chronic granulomatous inflammatory process is almost exclusively described in children and rarely forms discrete enhancing parenchymal nodules. We present the clinical and radiological features of an unusual case of chronic nodular granulomatous herpes encephalitis with enhancing “mass-like” nodules in an adult. To the author’s knowledge, this is the first reported case of macroscopic “mass-like” nodular granuloma formation in an adult.

Subacute Herpes Simplex Type 1 Encephalitis

“…Rare cases of histologically confirmed chronic granulomatous herpes encephalitis occurring in adults have been reported. 10 Subacute HSVE is rarely described in the literature being reported 4 times only (Table 1), and it was biphasic in 2 of them (our literature review was concluded on March 9, 2020). First case was by Hlavka et al, 11 as 58 years old woman with a biphasic course that lasted for 3 months.…”

“…Schutz et al9 noted that all published cases of biphasic chronic granulomatous HSVE were documented to have occurred in children. Rare cases of histologically confirmed chronic granulomatous herpes encephalitis occurring in adults have been reported 10…”