Case Report Intramedullary Conus Medullaris Tuberculoma: A Case Report and Review of the Literature Verajit Chotmongkol 1, Chinadol Wanitpongpun 1, Warinthorn Phuttharak 2 and Sittichai Khamsai 1,* 1 Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; [email protected] (V.C.); [email protected] (C.W.) 2 Department of Radiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; [email protected] * Correspondence: [email protected]; Tel.:+66-43-363664; Fax: +66-43-348399 Abstract: Intramedullary tuberculoma (IMT) of the conus medullaris is extremely rare. We present a case of intramedullary conus medullaris tuberculoma in which the diagnosis was based on there being very high levels of adenosine deaminase (ADA) in the patient’s cerebrospinal fluid (CSF) and improvement with antituberculous therapy. A 78-year-old man presented after having had a dull ache in both thighs and progressive paraparesis. The patient’s medical history included diffuse large B-cell lymphoma, which had undergone remission due to chemotherapy two years earlier, and long-term, well-controlled diabetes. A chest X-ray showed no evidence of tuberculosis. The results of CSF analysis were compatible with Froin’s syndrome. An initial diagnosis was made of an intramedullary tumor of the conus medullaris, based on magnetic resonance imaging (MRI). A myelotomy and multiple punch out biopsy were performed, and histopathology of the tissues revealed mild reactive gliosis. Due to the patient having high levels of CSF-ADA, IMT of the conus medullaris was suspected. The patient was treated with an 18-month course of antituberculous therapy. The dull ache gradually disappeared, and motor power improved slightly. A follow-up MRI of the lumbosacral (LS) spine revealed that the lesion had completely disappeared. Intramedullary tuberculoma of the conus medullaris should be considered in patients with underlying malignancy Citation: Chotmongkol, V.; and no symptoms of systemic tuberculosis. CSF adenosine deaminase levels can be helpful in Wanitpongpun, C.; Phuttharak, W.; determining the presence of central nervous system tuberculosis when other systemic signs of disease Khamsai, S. Intramedullary Conus are lacking. Medullaris Tuberculoma: A Case Report and Review of the Literature. Keywords: intramedullary tuberculoma; conus medullaris; adenosine deaminase; Froin’s syndrome Infect. Dis. Rep. 2021, 13, 82–88. https://doi.org/10.3390/idr13010010 Received: 16 November 2020 Accepted: 14 January 2021 1. Introduction Published: 15 January 2021 The most common type of neurotuberculosis is tuberculous meningitis (TBM). Early diagnosis and treatment with chemotherapy and active management of the complications Publisher’s Note: MDPI stays neu- are of great importance to prevent the irreversible neurologic sequel and death. A definite tral with regard to jurisdictional clai- diagnosis of TBM depends on identifying Mycobacterium tuberculosis in the cerebrospinal ms in published maps and institutio- fluid (CSF) by direct staining or culture. However, the diagnostic yield of CSF smears nal affiliations. and cultures has been very low, and mycological cultures may take up to six weeks to yield results [1]. Spinal intramedullary tuberculoma (IMT) is an uncommon disease, with roughly 170 cases having been reported to date. The most common site of involvement is Copyright: © 2021 by the authors. Li- the thoracic cord. The condition occurs in relatively young patients and is often associated censee MDPI, Basel, Switzerland. with extraspinal tuberculosis disease [2,3]. Intramedullary conus medullaris tuberculoma This article is an open access article is extremely rare. Here, we report a case of IMT of the conus medullaris in an elderly man distributed under the terms and con- with underlying lymphoma and diabetes. A diagnosis was made based on there being a ditions of the Creative Commons At- very high level of adenosine deaminase (ADA) in the patient’s cerebrospinal fluid (CSF) tribution (CC BY) license (https:// and improvement with antituberculous therapy. creativecommons.org/licenses/by/ 4.0/). Infect. Dis. Rep. 2021, 13, 82–88. https://doi.org/10.3390/idr13010010 https://www.mdpi.com/journal/idr Infect. Dis. Rep. 2021, 13 83 Infect. Dis. Rep. 2021, 13, FOR PEER REVIEW 2 2. Case Report A 78-year-old man presented after having had a dull ache in both thighs for six weeks, and progressive paraparesis for one week. He had a history of diffuse large B- 2. Case Report cell lymphoma with symptoms of generalized lymphadenopathy and splenomegaly, for which heA had78-year-old undergone man apresented complete after course having of chemotherapy had a dull ache (R-CHOP), in both thighs leading for to six disease weeks, and progressive paraparesis for one week. He had a history of diffuse large B-cell remission two years prior. He also had long term, well-controlled diabetes. General and lymphoma with symptoms of generalized lymphadenopathy and splenomegaly, for systemicwhich he examinations had undergone were a complete normal. course Motor of power chemotherapy of both (R-CHOP), lower limbs leading was 1/5to dis- with an absenceease remission of deep tendontwo years reflexes prior. andHe also joint had position long term, sense. well-controlled The remaining diabetes. of the General neurological examinationand systemic was examinations normal. were normal. Motor power of both lower limbs was 1/5 with anLumbosacral absence of deep plexopathy tendon reflexes was and initially joint diagnosed,position sense. caused The remaining by infection of the or neuro- lymphoma involvement.logical examination A lumbar was normal. puncture was performed and xanthochromic CSF was found. CerebrospinalLumbosacral fluid plexopathy analysis revealed was initially a white diagnosed, blood caused cell count by infection of 2 cells/mm or lymphoma3, a protein concentrationinvolvement.of A lumbar 2181 mg/dl, puncture and was a perfor glucosemed concentration and xanthochromic of 57.9 CSF mg/dl was found. (concurrent Cer- a bloodebrospinal glucose fluid concentration analysis revealed of 115 a white mg/dl). blood Gram cell count stain, of Ziehl–Neelsen 2 cells/mm3, a protein stain,Indian con- ink preparation,centration of cryptococcal 2181 mg/dl, antigen,and a glucose and cultureconcentration were of all 57.9 negative. mg/dl (concurrent The CSF culture, a blood which wasglucose subsequently concentration reported, of 115 was mg/dl). also Gram negative stain, for ZiehlM.– tuberculosisNeelsen stain,. Adenosine Indian ink deaminaseprepara- lev- tion, cryptococcal antigen, and culture were all negative. The CSF culture, which was sub- els in the CSF will help in determining the presence of central nervous system tuberculosis, sequently reported, was also negative for M. tuberculosis. Adenosine deaminase levels in which was determined by an automated method, were 30.9 U/L. Cytopathological and flow the CSF will help in determining the presence of central nervous system tuberculosis, cytometricwhich was analysis determined of the by CSF an automated demonstrated method, no evidencewere 30.9 U/L. of malignant Cytopathological lymphoma. and Due to theflow patient’s cytometric high analysis CSF proteinof the CSF concentration demonstrated but no normalevidence cell of malignant count (Froin’s lymphoma. syndrome), magneticDue to the resonance patient’s imaging high CSF (MRI) protein of concen the lumbo-sacraltration but normal (LS) spine cell count was performed(Froin’s syn- to rule outdrome), a spinal magnetic cord compression, resonance imaging and it(MRI) showed of the a lumbo-sacral 4.5 × 1.5 cm (LS) intramedullary spine was performed expanding lesionto rule at theout T12-L1a spinal level.cord compression, The lesion wasand it isointense showed a on4.5 T1-weighted× 1.5 cm intramedullary and hyperintense ex- onpanding T2-weighted lesion andat the short T12-L1 tau level. inversion The lesi recoveryon was isointense (STIR) images, on T1-weighted and exhibited and hyper- enhanced homogeneouslyintense on T2-weighted after contrast and short administration. tau inversion Diffuse recovery spinal (STIR) cord images, edema and above exhibited the lesion wasenhanced also detected homogeneously (Figure1 after). The contrast results administration. of a chest X-ray Diffuse were spinal within cord the edema normal above limits. Anti-HIVthe lesion was was non-reactive. also detected A(Figure T12-L1 1). The laminectomy results of a waschest performed, X-ray were within revealing the normal an enlarged conuslimits. with Anti-HIV an irregular was non-reactive. surface. The A nerve T12-L1 roots laminectomy appeared was normal. performed, A right-side revealing myelotomy an enlarged conus with an irregular surface. The nerve roots appeared normal. A right-side and multiple punch out biopsy were performed. Histopathology of the tissues revealed myelotomy and multiple punch out biopsy were performed. Histopathology of the tissues mildrevealed reactive mild gliosis. reactive Neither gliosis. granuloma Neither gr noranuloma a tumor nor wasa tumor found was then found Ziehl–Neelsen then Ziehl– stain andNeelsen tissue stain culture and for tissueM.tuberculosis culture for M.tuberculosiswere not performed. were not performed. After the operation, After the opera- the patient sufferedtion, the from patient urinary suffered retention, from urinary which retention, did not resolve.which did not resolve. (A) T1WI (B) STIR image (C) T1WI-FS with Gd FigureFigure 1. Magnetic 1. Magnetic resonance resonance