Paracoccidioidomycosis of the Central Nervous System: CT and MR Imaging Findings

Abstract

BACKGROUND AND PURPOSE: Paracoccidioidomycosis is a fungal infection mainly caused by the thermodimorphic fungus Paracoccidioides. The purpose of our study was to demonstrate the neuroimaging findings from 24 patients with CNS paracoccidioidomycosis. MATERIALS AND METHODS:We performed a retrospective analysis focusing on the radiologic characteristics of CNS paracoccidioidomycosis. The 24 selected patients underwent MR imaging and/or CT, and the diagnosis was made by the presence of typical neuroimaging features, combined with fungus isolation, a serologic test, or the presence of disseminated disease. RESULTS:Headache was the most common neurologic symptom, while the pseudotumoral form was the most common pattern. The number of lesions ranged from 1 to 11, with most localized on the frontal lobe with .2-cm lesions. CT showed mainly hypoattenuating lesions, whereas MR imaging demonstrated mainly hyposignal lesions on T1WI and T2WI. Furthermore, ring enhancement was present in most patients. The "dual rim sign" on SWI occurred in 100% of our patients with lesions of .2 cm. CONCLUSIONS:The diagnosis of CNS paracoccidioidomycosis is difficult. Nevertheless, imaging examinations can play an important role in the diagnosis and evaluation of the disease.ABBREVIATIONS: PCM ¼ paracoccidioidomycosis; CT ¼ computed tomography; MRI ¼ magnetic resonance imaging; CNS ¼ central nervous system; DSC ¼ dynamic susceptibility contrast; DCE ¼ dynamic contrast enhanced; rCBV ¼ relative cerebral blood volume; Gd ¼ gadolinium P aracoccidioidomycosis (PCM) is a fungal infection, which is endemic in Latin America and is mainly caused by the thermodimorphic fungus Paracoccidioides spp, which primarily attacks the lungs and has a potential to disseminate to other organs. 1 Recently described are 4 other species of the genus Paracoccidioides apart from P brasiliensis: P lutzii, P restrepiensis, P venezuelensis, and P Americana. 2,3 Paracoccidioides spp inhabits primarily the soil and causes autochthonous infection from southern Mexico to northern Argentina. 4-6 Most reported cases (approximately 80%) are from Brazil, and the rest are mainly from Venezuela, Colombia, and Argentina. [6][7][8][9][10][11][12][13][14] The criterion standard for the diagnosis of PCM consists of demonstrating the presence of the fungus as multiple budding cells in clinical or tissue specimens. Nevertheless, serologic tests and imaging examinations such as CT, MR imaging, and x-rays also play an important role in the diagnosis and evaluation of the disease. 1,[5][6][7][8][9][10][11][12][13][14][15][16][17] CNS involvement is more common than it was once believed, and the disease can affect the CNS, ranging from 1% to 27.27% of cases. [18][19][20][21][22][23][24][25] Although the brain form of PCM is usually an outcome of hematogenous or lymphatic dissemination of a primary focus, it is not necessarily followed by disseminated PCM; in a few cases, it is the only location of the fungus in the body. 26 Our purpose was to describe the clinical and radiologic data (CT ...

Neuroparacoccidioidomycosis: A 13-Year Cohort Study, Rio de Janeiro, Brazil

“…Imaging studies using computerized tomography (CT) showed a prevalence of 12.5% for NPCM among PCM patients without neurologic symptoms [ 11 ]. The increase in the availability and quality of imaging tests, when combined with the epidemiology and clinical manifestations, enabled a greater number of diagnoses [ 12 ].…”

“…Magnetic resonance imaging and CT scan besides helping in the NPCM diagnosis are important to locate and characterize the neural lesions. The cerebral hemispheres are affected in 62.5–65.0%, the cerebellum in 25.0–33.3%, the brain steam in 8.3–25.0%, and the spinal cord in 4.0% [ 8 , 12 ]. Our findings are in accordance with the literature data showing predominance of the involvement of the cerebral hemispheres.…”

“…The main radiological patterns are the pseudotumoral (87.5–90.0%), defined by the presence of parenchymal lesions with annular or nodular enhancement, and the meningeal (4.1–10.0%), characterized by inflammation of the leptomeninges or pachymeninges. The pseudotumoral lesions are frequently multiple (65.0%) [ 8 , 12 ]. All patients from this study presented pseudotumoral lesions, mostly multiple.…”

Multifocal Pseudotumorous Form of Neuroparacoccidioidomycosis in an Immunocompetent Patient: A Clinicopathological Review Based on a Case Report

“…Differential diagnosis includes Coccidioides immitis (sporangia measuring 30 µm to 60 µm and containing 1 µm to 5 µm sporangiosporesit usually occurs as meningitis), Histoplasma capsulatum (a dimorphic, ovoid fungi, measuring 2 µm to 5 µm), and Cryptococcus neoformans (yeasts measuring 4 µm to 7 µm and exhibiting a mucinous capsule). 1,2,7,12,13,19,20,22 In the presence of the pseudotumorous form of NPDM, the differential diagnosis also includes neoplasms (primary and secondary), abscesses, tuberculosis, and neurocysticercosis. 7,12,13,19,20,[22][23][24] The therapy includes sulfonamides, amphotericin B and azoles (fluconazole, itraconazole, voriconazole).…”

Paracoccidioidomicosis diseminada en paciente inmunocompetente: reporte de caso

“…Resto del examen bajo la normalidad. Al ingreso con los siguientes exámenes de laboratorio, en el hemograma: leucocitos 17,600/mm 3 , neutrófilos 14,200/mm 3 , linfocitos 2,400/mm 3 10, 8%, eosinófilos 300/mm 3 , plaquetas 513,000/mm 3 , hemoglobina 13,8 gr/dl, hematocrito 42,4%; función renal con creatinina 0,68 mg/dl y BUN 20,1 mg/dl; función hepática con AST 2, 280 U/L (valor de referencia 0-40 U/L) y ALT 1,800 U/L (valor de referencia 0-33 U/L); tiempo de coagulación con un PT 9,8 seg (9,(7)(8)(9)(10)(11)8 Se hospitalizó para realizar estudios de extensión con impresión diagnóstica de síndrome cruzado de tallo cerebral a nivel mesencefálico medial posiblemente secundario a lesión tumoral o enfermedad infecciosa expansiva. Al día siguiente, se valoró por Neurología quien consideró tomar tomografía axial computarizada (TAC) con contraste, que permitió identificar lesión hipodensa con realce en anillo a nivel frontal, además compromiso a nivel del tálamo, protuberancia, mesencéfalo del lado izquierdo acompañándose de edema con efecto compresivo local.…”