Single enhancing computerized tomography–detected lesion in immunocompetent patients

Abstract

<jats:p>Single enhancing computerized tomography (CT)–documented lesions may occur in several infectious and neoplastic diseases of the central nervous system and are the most common radiological abnormality seen in patients with acute-onset seizures in India and many other developing countries. Similar CT-documented lesions have also been reported in the developed world where these lesions are often considered to be caused by neoplasms or tuberculoma. Histopathological studies in India and even in some developed countries revealed that neurocysticercosis (NCC) is the most likely cause of these lesions provided they fulfill a rigid set of clinical and radiological criteria. Single cysticer-cus granuloma measures less than 20 mm in diameter, may be associated with cerebral edema not severe enough to produce midline shift, and occur in patients with seizures, normal neurological status, and no evidence of active systemic disease. When these lesions resolve spontaneously, either disappearing or changing into a calcified nodule, the diagnosis of NCC is very likely. The second most common cause of these CT-detected lesions is tuberculoma; in patients with these lesions similar clinical and neuroimaging features are also present. Few authors believe that in poor and developing countries, where both tuberculosis and NCC are common, it is difficult to differentiate between tuber-culoma and a single cysticercal granuloma. The most interesting feature of these solitary enhancing lesions is their spontaneous disappearance within weeks or months. Some lesions “heal” by becoming calcified. These patients require only antiepileptic therapy, and this medication may be withdrawn safely after the lesion has resolved on CT scanning. In several studies provision of anticysticercal drugs has been attempted, but because of conflicting results, their role in the management of these single lesions is uncertain. Neurosurgeons have a very limited role to play. In very rare situations, if the lesion increases in size and if focal neurological deficits manifest or seizures are uncontrolled, a brain biopsy sample may be required and histopathological evaluation performed to establish the correct diagnosis.</jats:p>

Immunological and molecular diagnosis of cysticercosis

“…[165][166][167] In Latin America, the proportion of NCC patients with a single-enhancing lesion varies from 3.5 to 34%, 168 likely reflecting different definitions of a single-enhancing lesion. More importantly, other infections, tumors, vascular lesions, and other etiologies need to be considered in the differential diagnosis of single brain lesions, [168][169][170] and thus serology could be of great help in saving unnecessary invasive procedures or treatments. 171 In general, all immunodiagnostic tests show low sensitivity for the diagnosis of single-lesional NCC, even worse when the lesion has entered in an involutive, degenerative process of resolution following antiparasitic treatment or by natural evolution ('single-enhancing lesion' or single cysticercal granuloma').…”

Features in Tubercular Meningoencephalitis Diagnosis: 18 Childhood Cases

“…Although CT and conventional MRI findings have been described for the diagnosis of tuberculomas and tuberculous abscess, these are non-specific characteristics of the disease in a number of patients. Tuberculomas and tuberculous abscess constitute approximately 10 to 20% of all intracranial masses: a single enhancing CT documented lesion may occur in several CNS infectious and neoplastic diseases and is the most common radiological abnormality seen in patients with acuteonset seizures [14] .…”

A Study on the Clinico-Radiological Profile and Outcome of Single Small Enhancing Lesions of the Brain

“…The rate of disappearance of lesion has ranged from 22 to 100% at 12 weeks after detection 14 . In a prospective study of 210 patients, Rajshekhar et al 15 observed that at 3 months only 19% of lesion had completely resolved; at 1 year approximately 63% had disappeared.…”