Granulomatous brain tumor caused by Acanthamoeba

J Neurosurg64:505-509, 1986 Granulomatous brain tumor caused by Acanthamoeba Case report S. KWAME OFORI-KWAKYE, M.D., DAVID G. SIDEBOTTOM, M.D., JOSEPH HERBERT, M.D., EDWIN G. FISCHER, M.D., AND GOVINDA S. VISVESVARA, PH.D. Departments of Neurosurgery, Infectious Diseases, and Neuropathology, Children "s Hospital, Boston; Departments of Surgery and Medicine, Harvard Medical School, Boston, Massachusetts; and Division of Parasitic Diseases, Centers for Disease Control, Atlanta, Georgia t/ A case of a previously healthy 7-year-old gift with a left frontoparietal tumor identified as an Acanthamoeba-induced granuloma is reported, and the literature on Acanthamoeba meningoencephalitis is reviewed, Unlike most reported cases, the Acanthamoeba central nervous system infection presented in this girl as a discrete tumor without meningeal involvement or diffuse encephalitis. A favorable outcome was obtained following total excision of the mass and treatment with ketoconazole. KEY WORDS 9 Acanthamoeba palestinensis 9 granuloma 9 cerebrum I T has long been known that central nervous system (CNS) amebiasis may result from visceral Entamoeba histolytica infectiony TM Infection of the CNS by free-living amebae, although known to occur, is generally not widely appreciated in discussions of human primary or secondary pathogens. We resected a left frontoparietal tumor that proved to be an Acanthamoeba-induced granuloma from a previously healthy 7-year-old girl. The case is presented, with a review of the literature on this unusual CNS infection. Case Report This 7-year-old girl was transferred to the Neurosurgery Service of the Children's Hospital, Boston, after a 2-week hospitalization at the Queen Elizabeth Hospital, Barbados. She was the product of a normal pregnancy and delivery; she weighed 2120 gm at birth, and had no neonatal problems. Her development from birth to age 5 years was unremarkable, and she had passed all the normal childhood milestones appropriately. On March 3 l, 1981, she was admitted to the Queen Elizabeth Hospital, complaining of a sensation of "insects crawling all over the body." Neurological examination at that time was unremarkable. A diagnosis of temporal lobe epilepsy was entertained and a course of carbamazepine was tried; the symptoms resolved and she was discharged home. About 6 months following this first hospitalization, and for the next 18 months, she was noted to have decreased appetite, was less active at home and in school, and often complained of frontal headaches. On October 23, 1983, her second admission to the Queen Elizabeth Hospital was occasioned by complaints of right upper extremity weakness of 3 days' duration and clumsiness at tasks that she could previously execute with dexterity. She also complained of a mild headache and vomited on several occasions. On physical examination on her second admission to the Queen Elizabeth Hospital she was afebrile and had normal vital signs. Cranial nerve examination was entirely normal and funduscopic examination showed no papilledema. Her right upper and lower extremities showed diminished motor strength (2/5), and there was hyperreflexia of the right upper extremity. Plantar responses were flexor bilaterally. She exhibited gross incoordination of the fight upper extremity and unsteadiness of gait on walking. Over the next 2 weeks at the Queen Elizabeth Hospital, the patient was noted to have progressive weakness of the right upper and lower extremities, with increased deep-tendon reflexes and a positive Babinski sign on the right. Subsequently, she developed a moderate right central facial palsy. She was transferred to the Children's Hospital, Boston, for further evaluation and care. J. Neurosurg. / Volume 64~March, 1986 505

S. K. Ofori-Kwakye, et al. FIG. 1. Computerized tomography scans, plain (a) and contrast-enhanced (b), obtained on presentation to the Children's Hospital, Boston. A large mass is revealed in the left parietal area. Examination. Computerized tomography (CT) on the day of admission (Fig. I a) showed a large mass in the left parietal area, extending from the vertex to the region of the third ventricle. Also noted were associated edema, effacement of the left lateral ventricle, and shift of the midline structures to the right. Administration of 50 cc metrizamide intravenously resulted in marked enhancement of the mass (Fig. lb). Operation. On November 18, 1983, a left parietal craniotomy was performed with excision of the tumor. The dura and cortex overlying the tumor appeared unremarkable. The interface between normal cortex and the tumor did not appear distinct. Postoperative Course. The patient did well postoperatively. She began treatment with intravenous amphotericin B, which was continued for the first 4 weeks postoperatively because of the initial clinical impression of focal fungal infection. Oral ketoconazole, 50 mg/ day, was administered starting 2 weeks postoperatively. The pathological diagnosis was confirmed by the successful culture of Acanthamoeba palistinensis excised from the tumor tissue, and the course of ketoconazole was continued alone for another 8 months. Followup CT scans 3 months after surgery showed persistent enhancement of the tumor bed. A subsequent scan showed disappearance of this contrast enhancement and only residual calcification at the operative site (Fig. 2). Pathological Examination. Grossly, the excised tumor tissue was gelatinous and displayed a mottled brownish-white appearance. Cortex and subcortical white matter were both involved, with poor definition of the interface between the two. Microscopically, the normal brain architecture was entirely replaced by multiple granulomata of varying sizes and an intense inflammatory response consisting of lymphocytes, plasma cells, histiocytes, and mononuclear granulocytes (Fig. 3). Amebic cysts ranging in FIG. 2. Computerized tomography scans with contrast enhancement obtained 1 year following resection of the tumor. Note the residual calcification at the operative site. size from 10 to 17 u were concentrated within the granulomata, often within giant cells or surrounded by radially aligned histiocytes (Fig. 4). A karyosome was present in some cysts, while others appeared empty. The cyst walls were mono- or bilayered and often appeared wrinkled. Gomori methanamine silver stained variably, but in some cases both the cyst wall and its contents were stained. Central zones of necrosis, sometimes mineralized, were present within the granulomata. Trophozoites were not identified. The tumor border was ill-defined, and many small granulomata and perivascular mononuclear infiltrates were found within otherwise unremarkable brain parenchyma distant from the granulomatous mass. Discussion Acanthamoeba is a free-living ameba found as part of the normal human flora 17'39 or in the environment. 21,22 The first observation on the pathogenicity of these flee-living amebae was made in 1958 by Culbert- FIG. 3. Photomicrograph of a section of the resected tumor. Note the granuloma with an amebic cyst surrounded by giant cells and radially aligned histiocytes. The normal brain cytoarchitecture is lost. H & E, x 195. 506 J. Neurosurg. / Volume 64 / March, 1986

Granulomatous brain tumor caused by Acanthamoeba son, et al., J3 when they injected tissue culture medium thought to contain simian virus intracerebrally into monkeys and mice. This produced a severe choriomeningitis in the mice. All the animals died, and the stained sections of their brains were found to contain rounded amebae. Culbertson, et al., later demonstrated that the amebae lived in the stored culture fluid from which the inoculum was prepared; they identified that isolate as Acanthamoeba species Lilly A-1. Further experimental infection of animals showed that when an inoculum of the amebae was instilled intranasally into mice, the organisms invaded the olfactory bulb through the cribriform plate and later infected the whole brain. 12 Culbertson 11 suggested that a similar manifestation could be produced in humans by inoculation of freeliving amebae into the nasal passage through activities such as swimming. His review of the protozoologic literature revealed that the experimental pathogenic ameba he had isolated was identical to organisms of the genus Hartmannella, according to the classification of Singh. 35 He therefore adopted the hyphenated name Hartmannella-Acanthamoeba for his pathogenic isolates. Some authors have adopted Culbertson's terminology, J~ but others prefer to separate the two types of organisms since, as far as is known, no organisms of the genus Hartmannella are pathogenic for man. J6 In 1965, Fowler and Carter 15 were the first to report a fatal CNS infection due to free-living amebae. They identified the pathogenic organisms as Acanthamoeba but subsequent studies have proved the organism to be Naegleria fowleri, ~6 another pathogenic free-living ameba that causes human CNS infection. In 1966, Butt 4 described the first case of human infection due to Naegleria in the United States. He coined the term "primary amebic meningoencephalitis" to distinguish CNS infection caused by the free-living amebae from CNS infection that is secondary to Entamoeba histolytica gastrointestinal amoebiasis. Observations over the years indicate that there are two fairly distinct clinical entities caused by CNS infection by the free-living amebae. Naegleriafowleri causes an acute fulminating disease generally leading to death within 5 to 10 days. The patients are characteristically young and healthy, and often give a history of exposure to fresh-water swimming about a week before the onset of the fatal disease. Subsequent autopsy studies often show destruction of the olfactory bulbs occurring before the severe choriomeningitis. This may suggest the nasal mucosa as the primary portal of entry. Naegleriafowleri infection is identical to the primary amebic meningoencephalitis of Butt. 4 Acanthamoeba species may cause a fatal illness but, unlike N. fowleri, the disease is of a chronic nature and may last from a few weeks to several months. Infection occurs principally in debilitated, chronically ill individuals with compromised immune defenses. A history of fresh-water swimming is not often elicited. Aeanthamoeba infection is termed "granulomatous amebic encephalitis" (GAE). 26 Up to July, 1983, nearly 30 cases ofacanthamoeba GAE have been reported world-wide since the initial report in 1965 by Fowler and Carter. 26 Primary amebic meningoencephalitis and GAE may be FIG. 4. Photomicrographs showing organisms within the cytoplasm of a giant cell (a) and surrounded by radially aligned histiocytes (b). H & E, x 400. J. Neurosurg. / Volume 64/March, 1986 507

S. K. Ofori-Kwakye, et al. confused, and some of the earlier clinical and pathological reports of Acanthamoeba infection are in fact cases of N. fowleri infection. 3-7'9'15'23,32 In addition to fatal or chronic CNS infection, Acanthamoeba also causes other infections such as corneal ulcers, uveitis, otitis, and pulmonary disease. 19,38 The earliest reliable report of Acanthamoeba CNS infection is that of Kernohan, et a/. 2~ They described a fatal intracranial infection in a 6-year-old girl and attributed it to Iodamoeba bfttschlii. The amebae were probably introduced via a scalp wound sustained almost a year prior to her fatal illness. The amebae involved in that case have been identified by immunoperoxidase staining as A. culbertsoni. 28 Several recent reports by Martinez, et al.,25.27,29 have outlined a distinct clinical and pathological picture that reinforces most of the previously cited observations on Acanthamoeba infections. They indicated that all of the patients reported by their group were immunosuppressed; complete documentation of the degree of immunosuppression is not provided, but the idea of an otherwise benign free-living pathogen that produces a chronic granulomatous infection in an immunosuppressed host has precedence. Acanthamoeba produces a severe granulomatous inflammation particularly in the brain stem and posterior fossa structures. The lesions are usually multiple but rarely is the infection limited to a discrete single focus simulating an intracranial malignancy, as was the case in our patient. In all previously reported cases, the patients exhibited a cerebrospinal fluid (CSF) pleocytosis. The CSF was not examined in our patient. It is possible that CSF pleocytosis was present transiently but was not detected in her earlier clinical evaluations. The portal of entry of the organism was not clear in the observations reported by Martinez and coworkers. They believed that the nasal mucosa was an unlikely portal since the olfactory bulbs were intact at autopsy, unlike reports on victims of Naegleria infection. Direct invasion from an ocular source 19 or from other surface infection is possible. ~'3 Martinez, et al, 29 pointed out that a primary pulmonary site of inoculation with hematogenous dissemination to other body organs is equally likely, since they have also identified Acanthamoeba cysts and trophozoites in extracerebral locations, with an associated inflammatory response. Our patient did not give a history of swimming or playing in tepid water, and could have acquired the infection through a portal other than the nose. At present, there is no clearly efficacious chemotherapeutic agent for treatment of Acanthamoeba infection. Several in vitro studies have documented the reaction of Acanthamoeba species to many antibacterial, antifungal, and antiprotozoal agents. 8'14'30'33'34'36'37 In vitro studies by Visvesvara, et "a/., 38 of the isolate identified in our case have revealed some sensitivity to ketoconazole, amphotericin B, sulfadiazine, and neomycin at 12.5, 50.0, 25, and 20 ug/ml, respectively. Sulfadiazine in vitro is thought to have some effect, 8 and this is supported by the clinical report of Cleland, et al., 1~ who reported an Acanthamoeba (Hartmannella) rhysodes-induced infection in a Nigerian patient. Recent laboratory observations 14 also suggest that phenothiazine compounds may have some effect upon both Acanthamoeba and Naegleria. This would be especially advantageous, since most of the compounds found to be active in vitro do not penetrate into the CNS in the predicted clinically effective levels. It would appear that complete surgical excision of the mass lesion, combined with chemotherapy, offers the best prognosis, in addition to offering tissue for a definitive diagnosis. Our patient's clinical course has been characterized by slow resolution of her original right hemiparesis. The mechanisms by which she has been able to contain a usually fatal CNS infection are not clear. She has shown histopathological evidence of a quite successful inflammatory response to the parasites, and an intact immunological structure and function have been demonstrated by numerous laboratory tests done at our clinic. The role of immunosuppression in CNS Acanthamoeba infection and its effect on the clinical course are unknown aspects of the disease certainly worthy of further investigation. References 1. Apley J, Clarke SKR, Roome APCH, et al: Primary amoebic meningoencephalitis in Britain. Br Med J 1: 596-599, 1970 2. Banerjee AK, Bhatnagar RK, Bhusnurmath SR: Secondary cerebral amebiasis. Trop Gengr Med 35:333-336, 1983 3. Bhagwandeen SB, Carter RF, Naik KG, et al: A case of Hartmannellid amebic meningoencephalitis in Zambia. Am J Clin Pathnl 63:483-492, 1975 4. Butt CG: Primary amebic meningoencephalitis. N Engl J Med 274:1473-1476, 1966 5. Callicott JH Jr: Amebic meningoencephalitis due to freeliving amebas of the Hartmannella (Acanthamoeba)- Naegleria group. Am J Clin Pathnl 49:84-91, 1968 6. Callicott JH Jr, Nelson EC, Jones MM, et al: Meningoencephalitis due to pathogenic free-living amoeba. Report of two cases. JAMA 206:579-582, 1968 7. Carter RF: Primary amoebic meningo-encephalitis: clinical, pathological and epidemiological features of six fatal cases. J Pathnl Bacterinl 96:1-25, 1968 8. Casemore DP: Sensitivity of Hartmannella (Acanthamoeba) to 5-fluorocytosine, hydroxystilbamidine, and other substances. J Clin Pathol 23:649-652, 1970 9. Cerva L, Novak K: Amoebic meningoencephalitis: sixteen fatalities. Science 160:92, 1968 10. Cleland PG, Lawande RV, Onyemelukwe G, et al: Chronic amebic meningoencephalitis. Arch Nenrnl 39: 56-57, 1982 11. Culbertson CG: Pathogenic Naegleria and Hartmannella (Acanthamoeba). Ann NY Acad Sci 174: 1018-1022, 1970 12. Culbertson CG, Smith JW, Cohen HK, et al: Experimental infection of mice and monkeys by Acanthamoeba. Am J Pathol 35:185-197, 1959 13. Culbertson CG, Smith JW, Minner JR: Acanthamoeba: 508 J. Neurosurg. / Volume 64/March, 1986

Granulomatous brain tumor caused by Acanthamoeba observation on animal pathogenicity. Science 127:1506, 1958 14. Duma RJ, Finley R: In vitro susceptibility of pathogenic Naegleria and Acanthamoeba species to a variety of therapeutic agents. Antimicrob Agents Chemother 10:370-376, 1976 15. Fowler M, Carter RF: Acute pyogenic meningitis probably due to Acanthamoeba sp.: a preliminary report. Br Med J 2:740-742, 1976 16. Griffin JL: Pathogenic free-living amoebae, in Kreier JP (ed): Parasitic Protozoa. New York: Academic Press, 1978, Vol 2, pp 508-549 17. Jadin JB: De la dispersion et du cycle des amibes libres. Ann Soc Belg Med Trop 54:371-385, 1974 18. Jager BV, Stamm WP: Brain abscesses caused by freeliving amoeba probably of the genus Hartmannella in a patient with Hodgkin's disease. Lancet 2:1343-1345, 1972 19. Jones DB, Visvesvara GS, Robinson NM: Acanthamoeba polyphaga keratitis and Acanthamoeba uveitis associated with fatal meningoencephalitis. Trans Ophthalmol Soc UK 95:221-232, 1975 20. Kernohan JW, Magath TB, Schloss GT: Granuloma of brain probably due to Endolimax williamsi (Iodamoeba bfttschlii). Arch Pathol 70:576-580, 1960 21. Kingston D, Warhurst DC: Isolation of amoebae from the air. J Med Microhioi 2:27-36, 1969 22. Lawande RV, Abraham SN, John I, et at: Recovery of soil amebas from nasal passages of children during the dusty Harmattan period in Zaria. Am J Clin Pathol 71: 201-203, 1979 23. Lawande RV, Duggan MB, Constantinidou M, et al: Primary amoebic meningoencephalitis in Nigeria (report of two cases in children). J Trop Med Hyg 82:84-88, 1979 24. Lombardo L, Alonso P, Arrayo LS, et al: Cerebral amebiasis. Report of 17 cases. J Neurosurg 21:704-709, 1964 25. Martinez A J: Acanthamoebiasis and immunosuppression. Case report. J Neuropathol Exp Neuro141:548-557, 1982 26. Martinez A J: Free-living amoebae: pathogenic aspects. A review. Protozool Abstracts 7:293-306, 1977 27. MartinezAJ: Is Acanthamoeba encephalitis an opportunistic infection? Neurology 30:567-574, 1980 28. Martinez A J, Garcia CA, Halks-Miller M, et al: Granulomatous amebic encephalitis presenting as a cerebral mass lesion. Acta Neuropathol 51:85-91, 1980 29. Martinez AJ, Sotelo-Avila C, Garcia-Tamayo J, et al: Meningoencephalitis due to Acanthamoeba sp. Patho- genesis and clinico-pathological study. Acta Neuropathol 37:183-191, 1977 30. Nagington J, Richards JE: Chemotherapeutic compounds and Acanthamoebae from eye infections. J Clin Pathol 29:648-65 l, 1976 31. Orbison JA, Reeves N, Leedham CL, et al: Amebic brain abscess. Review of the literature and report of five additional cases. Medicine 30:247-282, 195t 32. Patras D, Andujar J J: Meningoencephalitis due to Hartmannella (Acanthamoeba). Am J Clin Pathol 46: 226-233, 1966 33. Rowan-Kelly B, Ferrante A, Thong YH: The chemotherapeutic value of sulphadiazine in treatment of Acanthamoeba meningoencephalitis in mice. Trans R Soc Trop Med Hyg 76:636-638, 1982 34. Schuster FL, Mandel N: Phenothiazine compounds inhibit in vitro growth of pathogenic free-living amoebae. Antimicrob Agents Chemother 25:109-112, 1984 35. Singh BN: Nuclear division in nine species of free-living amoebae and its bearing on the classification of the order Amoebida. Philos Trans R Soc Lond Ser B 236: 405-461, 1952 36. Stevens AR, O'Dell WD: In vitro and in vivo activity of 5-fluorocytosine on Acanthamoeba. Antimicrob Agents Chemnther 6:282-289, 1974 37. Stevens AR, Shulman ST, Lansen TA, et al: Primary amoebic meningoencephalitis: a report of two cases and antibiotic and immunologic studies. J Infect Dis 143: 193-299, 1981 38. Visvesvara GS, Mirra SS, Brandt FH, et al: Isolation of two strains of Acanthamoeba castellanii from human tissue and their pathogenicity and isoenzyme profiles. J Clin Microbini 18:1405-1412, 1983 39. Wang SS, Feldman HA: Isolation of Hartmannella species from human throats. N Engl J Med 277: 1174-1179, 1967 40. Willaert E, Stevens AR, Healy GR: Retrospective identification of Acanthamoeba culbertsoni in a case of amoebic meningoencephalitis. J Clin Pathol 31: 717-720, 1978 Manuscript received May 21, 1985. Accepted in final form July 23, 1985. Address for Dr. Visvesvara: Division of Parasitic Diseases, Centers for Disease Control, Atlanta, Georgia. Address reprint requests to: S. Kwame Ofori-Kwakye, M.D., Department of Neurosurgery, Children's Hospital, 300 Longwood Avenue, Boston, Massachusetts 02115. J. Neurosurg. / Volume 64/March, 1986 509