unusual computed tomographic presentation of cerebral

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45 8 Unusual Computed Tomographic Presentation of Cerebral Toxoplasmosis Sergio Mazer ,' Joao Candido Araujo, 2 Raul Correia Ribeiro,3 and Gilda Kasting4 The computed tomog r aphic appearance of three cases of cerebral toxoplasmosis is described. Two of the patients were children with Hodgkin disease and the third was an adult with syst emic lupus erythematosus . All patients were severely im- munosuppressed . Computed tomography showed single or mul- tiple hypodense rounded areas with peripheral annular contrast enhancement , suggesting pyogenic cerebral abscesses . Patho- logic correlation is presented. The importance of di agnosis and early treatment is emphasized . Toxoplasmosis is a protozoan infection produ ced by Toxoplasma gondii , which may be eith er co ngenital or acquired. Acute infec tion of th e ce ntr al nervous system has been report ed with in creas in g frequency in immunosuppressed pati ent s [ 1-4], particula rl y in those with neop lasms of the hematopoietic system [5, 6]. Several types of lesions of the central nervous system have been desc ribed un de r these c ircumstances, including " mass lesions" demonstr ated by co mputed tomography (CT) [ 7-9]. This paper reports two cases with similar eT findings diagnosed postmortem and a thir d case successfully tr eated. Case Reports Ca se 1 A 9-year-old boy with a hard mass in his right axilla and several small cervica l and inguinal lymph nodes had a diagnosis of Hodgkin disease established by biopsy of one of the cervica l lesions. Tr eat- ment with mechl ore thamine, Onco vin , proca rbazine, and predni- sone (MOPP) was started. Nine months later he returned with headache, do uble vision, vomiting, and drowsiness. Ne urologic examination showed papilledema, right VI nerve palsy, and left central f acial weak ness. Routine laboratory tests were unremarka- ble. eT showed two round lesions with ringlike co ntrast enhancement surrounded by edema, one in each ce rebral hemisphere (fi gs . 1 A and 1 B). Ten days later ano th er eT stu dy revealed enlar ge men t of both lesions and a small left thalami c nodule. IgM and IgG immu- nofluorescence antib ody tests f or toxoplasmosis were nega ti ve. Biop sy of the right parietal lesion showed nonspecific inflammatory ti ssue. Neurologic status progre ssively de teriorated, and the patient died. At autopsy, a right parietal hematoma was found at the site of biopsy. Posteri or to the hematoma a nodular gray lesion was iden- tified. Microsco pic examination revealed a mononuclear infiltrate and pseud ocysts co ntaining Toxoplasma gondii tro phozoites (fig. 1 e). Another similar lesion was found in the left occ ipital lobe, in addition to multiple punctate similar lesions elsewhere in the brain . Case 2 A 22-year-old man was admitt ed with progressive left hemi- paresis, headache, and somnolence . A diagnosi s of systemic lupus erythematosus had been made 4 years earlier, and he had been tr eated with prednison e, cyclophosphamid e, and mercapt opurine. A diagnosis of pulmonary tuber culosis 2 years before admission led to succ essful tr eatment with str eptomycin, rifamycin, and Myam- butol over a period of 1 year. Physica l examination was normal exc ept for left hemiparesis and hyperreflexia. Laboratory tests were normal. Lupus erythemato sus ce lls we re not found, and cerebro- spinal fluid examination revealed only abnormally elevated protein levels. eT (fig. 2A) showed a 3 cm round lesion involving the basal ga nglia on the right with a ce ntral zone of low density s urrounded by an enc ircling ring of co nt rast enhance ment. There was edema in th e s urrounding white matter. Bi opsy of the lesion demonstr ated only nonspec ific inflammatory changes. The patient died on post- operative day 25 due to respiratory complications. At autopsy, a Single brain lesion was found, measuring 3 x 4 cm, involving the right basal ganglia , thalamus, and internal capsul e (fig. 2B), formed by granulomatous and nec rotic tissues cont aining many encysted microorganisms charac terized as Toxoplasma g ondii. Ca se 3 A 5-year-old boy was admitted with an 8 month hist ory of fever and weig ht loss. On examination, enlar ge ment of the cervica l lymph nodes, li ve r, and spleen were noted. A diagnosis of Hodgkin dis- ease, mixed cellularity, st age IIIB, was made by lymph node bi opsy and laparo tomy, and treatment with MOPP was begun. Fi ve months later he returned with right hemiplegia and bilateral Babinski signs. eT showe d a round lesion 12 mm in diameter in the posterior po rtion of the basal ga ng li a on the ri ght with ringlike co ntrast enhance ment (fig. 3 A) , and several small irregul ar enhancing nod- ules involving the right pa ri etal and bo th occi pital lobes. , Department of Radiology, Hospital Nossa Senhora das Gra<;as and Hospital de Clinicas of the Federal University of Parana, Curitiba, Brazil. Address reprint requests to S. Mazer, Benjamin Constant. 90 / 113, 80.000 Curitiba, Brazil. 2 Department of Neuros urgery, Hospital Nossa Senhora das Gra<;as and Hos pital de Clinicas of the Federal University of Parand, Curitiba, Brazi l. 3 Department of Pediatrics, Hospital Nossa Senhora das Gra<;as and Hospital de Clinicas of th e Federal University of Parana, Curitiba, Brazi l. , Department of Pathology, Hospital Nossa Senhora das Gra<; as and Hos pital de Clinicas of the Federal University of Parana. Curitiba, Brazil. AJNR 4 :458-460, May / June 1983 0195-6 108 / 83 / 0403 -045 8 $00 .00 © Ameri ca n Roent gen Ray Society

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Page 1: Unusual Computed Tomographic Presentation of Cerebral

458

Unusual Computed Tomographic Presentation of Cerebral Toxoplasmosis Sergio Mazer,' Joao Candido Araujo, 2 Raul Correia Ribeiro, 3 and Gilda Kasting4

The computed tomographic appearance of three cases of cerebral toxoplasmosis is described. Two of the patients were children with Hodgkin disease and the third was an adult with systemic lupus erythematosus. All patients were severely im­munosuppressed. Computed tomography showed single or mul­tiple hypodense rounded areas with peripheral annular contrast enhancement, suggesting pyogenic cerebral abscesses. Patho­logic correlation is presented. The importance of d iagnosis and early treatment is emphasized.

Toxoplasmosis is a protozoan infection produced by Toxoplasma gondii , which may be either congenital or acquired . Ac ute infection of the central nervous system has been reported with increasing frequency in immunosuppressed patients [ 1-4], parti cularl y in those with neoplasms of the hematopo ietic system [5, 6]. Several types of lesions of the central nervous system have been described under these c ircumstances, including " mass lesions" demonstrated by computed tomography (CT) [7-9]. This paper reports two cases with similar eT findings diagnosed postmortem and a third case successfully treated .

Case Reports

Case 1

A 9-year-old boy with a hard mass in his right axilla and several small cervical and inguinal lymph nodes had a diagnosis of Hodgkin disease established by biopsy of one of the cervical lesions. Treat­ment with mechlorethamine, Oncovin , procarbazine, and predni­sone (MOPP) was started . Nine months later he returned with headache, double vision, vom iting , and drowsiness. Neurolog ic examination showed papilledema, r ight VI nerve palsy , and left central facial weakness. Routine laboratory tests were unremarka­ble.

eT showed two round lesions with ringlike contrast enhancement surrounded by edema, one in each cerebral hemisphere (figs. 1 A and 1 B) . Ten days later anoth er e T study revealed enlargemen t of both lesions and a small left thalamic nodule. IgM and IgG immu­nofluorescence an tibody tests for toxoplasmosis were negati ve. Biopsy of the right parietal lesion showed nonspecifi c inflammatory ti ssue. Neurolog ic status progressively deteriorated , and the pat ient died.

At autopsy, a right parietal hematoma was found at the site of biopsy. Posterior to th e hematoma a nodu lar gray lesion was iden­tified . Microscopic examination revealed a mononuclear infiltrate and pseudocysts containing Toxoplasma gondii trophozoites (fig . 1 e ). Another similar lesion was found in the left occipital lobe, in addition to multiple punctate similar lesions elsewhere in the brain .

Case 2

A 22-year-old man was admitted with prog ressive left hemi­paresis, headache , and somnolence. A diagnosis of systemic lupus erythematosus had been made 4 years earlier, and he had been treated with prednisone, cyc lophosphamide, and mercaptopurine. A diagnosis of pulmonary tuberculosis 2 years before admission led to successful treatment with streptomycin, rifamycin , and Myam­butol over a period of 1 year . Physical examination was normal except for left hemiparesis and hyperreflexia. Laboratory tests were normal. Lupus erythematosus cells were not found, and cerebro­spinal flu id examination revealed only abnormally elevated protein levels.

e T (fig . 2A) showed a 3 cm round lesion involving th e basal ganglia on the right with a central zone of low density surrounded by an encirc ling ring of contrast enhancement. There was edema in the surrounding white matter. Biopsy of the lesion demonstrated only nonspecific inflammatory changes. The patient died on post­operative day 25 due to respiratory complications. At autopsy, a Single brain lesion was found, measuring 3 x 4 cm , involving the right basal ganglia, thalamus, and internal capsule (fig. 2B) , formed by granulomatous and necrotic tissues containing many encysted microorganisms characterized as Toxoplasma gondii.

Case 3

A 5-year-old boy was admitted wi th an 8 month history of fever and weight loss. On examination, enlargement of the cervical lymph nodes, liver, and spleen were noted . A diagnosis of Hodgkin dis­ease, mixed cellularit y, stage IIIB , was made by lymph node biopsy and laparotomy, and treatment with MOPP was begun . Five months later he returned with right hemipleg ia and bilateral Babinski signs. e T showed a round lesion 12 mm in diameter in the posterior portion of the basal ganglia on the right with ring like contrast enhancement (fig . 3 A) , and several small irregular enhancing nod­ules involving the r ight parietal and both occipi tal lobes .

, Department of Radiology, Hospital Nossa Senhora das Gra<;as and Hospital de Clinicas of the Federal University of Parana, Curitiba, Brazil. Address repri nt requests to S. Mazer, Benjamin Constant. 90 / 113, 80 .000 Curi tiba, Brazil.

2 Department of Neurosurgery, Hospital Nossa Senhora das Gra<;as and Hospital de Clinicas of the Federal University of Parand, Curi tiba, Brazi l. 3 Department of Pediatrics, Hospital Nossa Senhora das Gra<;as and Hospital de Clin icas of the Federal University o f Parana, Curi tiba, Brazi l. , Department of Pathology, Hospital Nossa Senhora das Gra<;as and Hospital de Clinicas of the Federal University of Parana. Curitiba, Brazil.

AJNR 4 :458-460, May/ June 1983 0 195-6108 / 83 / 0403-0458 $00.00 © American Roentgen Ray Soc iety

Page 2: Unusual Computed Tomographic Presentation of Cerebral

AJNR:4, May/June 1983 CT OF THE HEAD 459

A B

c Fig . 1 .-Case 1. CT presentation of toxoplasmosis lesions in patient with

diagnosis of Hodgkin disease. A, Round lesion with peripheral ringlike contrast enhancement and surrounding edema in right parietal lobe. B, Incomplete ring of con trast enhancement and ad jacent semic ircu lar lesion, both surrounded by white matter edema, in left temporooccipital reg ion. C, Microscopic examination showing pseudocysts containing Toxoplasma gon­dii Irophozoites.

Considering the experience acquired with the previous cases and despite negative IgM and IgG immunofluorescence antibody tests, a presumptive diagnosis of toxoplasmosis was made. The patient was treated with pyrimethamine, sulfonamide, and leuko­vorin with total disappearance of the clinical symptomatology . A repeat CT study 1 month later was normal (fig . 38). On c linica l reevaluation 7 months later the patient was neurologically intact.

Discussion

Toxoplasmosis involving the central nervous system may have several different clinical and pathological presentations, inc luding hyd rocephalus with multiple intracerebral ca lc ified lesions, which are easily detected by CT. A growing number of cases presenting as one or several intracerebral " mass lesions" are being reported [10, 11] in patients with disturbances of their immunologic systems, notably those harboring neoplasms of the hematopoietic system and / or undergoing treatment with immunosuppressive drugs. In these patients, due to impai red immune reaction, serologic tests

A B Fig . 2. - Case 2. CT presentation of toxoplasmosis lesions in patient with

diagnosis of lupus erythematosus. A, 3-cm-d iameter sing le-contrast enhanc­ing ring lesion with central hypodense area and ex tensive surrounding edema in right basal ganglia. B, Corresponding area o f granulomatous and necrotic tissues that contained Toxoplasma parasites.

A B Fig. 3. -Case 3. A, Pretreatment scan. Round lesion with peripheral

ringlike contrast enhancement involving right basal ganglia posteriorly. Ad­ditiona l irregular enhanc ing lesions in both occipital lobes. B, Repeat postcon­trast scan 1 month after specific therapy for toxoplasmosis is normal.

may be negative for toxoplasmosis [3] despite the presence of active disease, as exemplified in ou r cases 1 and 3. Th e lesions demonstrated by CT are usually nonspeci fi c, and th e differen tial diagnosis inc ludes all single or multiple ring li ke lesions, main ly pyogenic abscesses, gliomas, and intracerebral metastases. The central area of necrosis and the peripheral granulation ti ssue sur­rounded by edematous cerebral tissue account for the annular appearance of the " toxoplasmomas" on CT.

Toxoplasmosis, a potentially fatal disease in immunosuppressed pat ients, may be successfully treated. Therefore, we suggest that even in the absence of posit ive biopsy or labortory data, when findings similar to those described above are shown by CT in immunosuppressed patients , c linical suspic ion of toxoplasmosis shou ld be raised and vigorous treatment initiated.

Page 3: Unusual Computed Tomographic Presentation of Cerebral

460 CT OF THE HEAD AJNR :4, May / June 1983

REFERENCES

1. Bamford CR. Toxoplasmosis mimicking a brain abscess in an adult with treated scleroderma. Neurology (NY) 1975;25: 343-345

2. Townsend JJ , Wolinski JS, Baringer JR, Johnson PC. Acquired toxoplasmosis. Arch NeuroI1975;32: 335-343

3. Ruskin J, Remington JS. Toxoplasmosis in the compromised host. Ann Intern Med 1976;84 : 1 93-199

4. Emerson RG , Jardine OS, Milvenan ES, et al. Toxoplasmosis: a treatable neurologic disease in the immunologically compro­mised patient. Pediatrics 1981 ;67 : 653-655

5. Carey RM , Kimball AC, Armstrong 0 , Lieberman PH. Toxo­plasmosis-clinical experiences in a cancer hospital. Am J Med 1973;54: 30-38

6 . Masson R, Fiere 0, Lahneche B, Cordat CI , Berger F, Revol L.

Toxoplasmose encephalique pseudo-tumorale au cours d'une hemopathie. Nouv Presse Med 1975;18 : 2499-2502

7. Mcleod R, Berry PF, Marshall WH Jr, Hunt SA, Ryning FW, Remington JS. Toxoplasmosis presenting as brain abscesses. Am J Med 1979;67:711-714

8. Alenghat JP, Morris JH , Kido OK, Rumbaugh CL. Computed tomography in opportunistic cerebral toxoplasmosis. Comput Tomogr 1979;3: 413-416

9. Araujo JC, Cichon E, EI Sarraf R, Antoniuk A. Tumoral form of toxoplasmosis. In: Proceedings of the XVIII Latin American Congress of Neurosurgery. Buenos Aires, November 1979:261-263

10. Schulhof LA, Russel JR. Intracerebral toxoplasmosis present­ing as a mass lesion. Surg NeuroI1975;4: 9-11

11 . Tognetti F, Galassi E, Gaist G. Neurological toxoplasmosis presenting as a brain tumor. J Neurosurg 1982;56 : 716-721