A Girl with Painful Swollen Joints and Abdominal Ache, An Atypical Presentation of Disseminated Musculoskeletal TB: A Case Report

IntroductionJoint pain and swelling with abdominal aches are the initial presentation of many Rheumatological Diseases and Metabolic disorders, such as Hemochromatosis.However, Infections, either bacterial or viral, should always be considered an important differential diagnosis.Mycobacterium Tuberculosis is the second most common cause of Musculoskeletal Osteomyelitis, an infrequent entity accounting for 1.5 to 3 percent of all TB cases, occurring more often in young individuals and detected in later stages of the disease, predominantly affecting epiphysial and subchondral regions of bone.Occasionally, it disseminates to other body viscera and systems.We at this moment present a case of a 16year-old girl who explained to us with joint pain along with affected joints swelling for 9 months.In addition, she had abdominal pain in the same period in association with fever and weight loss for a few months.All baseline investigations were regular except for increased ESR and CRP.Autoimmune and ENA profiles were average.Among radiological investigations, USG's abdomen and pelvis were consistent with moderate pelvic ascites and normal musculoskeletal USG in all swollen joints.CT CAP scan showed axillary Lymphadenopathy and Pelvic Ascites.MRI scan of severely inflamed right knee joint with and without contrast studies couldn't lead to a satisfactory diagnosis.SPECT/CT scan of the same joint was performed, and studies highlighted Lytic lesions on the proximal tibial bone that were AFB positive on Microbiological analysis.The histopathological evaluation further confirmed the benign but Tuberculous Nature of the lesions.The purpose of this case report is to elaborate on an atypical aspect of the clinical presentation of Musculoskeletal TB, often misdiagnosed as seronegative arthritis or malignancy.Sometimes, it is due to a lack of definite radiological findings.A delay in initiating ATT would lead to secondary dissemination to other body systems. Case presentationWe report a case of a 16 years old Asian girl who had joint pain and swelling for a duration of 9 months along with fever and weight loss in association with abdominal pain of the same duration with no significant past medical and surgical as well as personal history except having positive contact with pulmonary TB in the family.ESR and CRP were raised.X-ray and Musculoskeletal skeletal USG of all affected joints didn't show abnormal findings.On abdominopelvic ultrasonography, moderate pelvic ascites were found (exudative, lymphocytic on diagnostic ascetic paracentesis) with no visceral enlargement or lymphadenopathy.CT CAP revealed nodal enlargement in the axillary area of one side of the body with pelvic ascites.MRI studies of actively inflamed right knee were not directed towards a reasonable diagnosis.SPECT/CT of the same joint revealed lytic lesions of proximal tibial bone; could it be malignant?After a CT-guided biopsy of suspicious lesions, specimens were sent for microbiology and histopathological examination.Finally, AFB smear staining was positive.Meanwhile, growth was detected on AFB culture as ++.ATT started instantly, and the patient's symptoms began improving within weeks. ConclusionIn adults with Musculoskeletal TB, Mycobacterium rarely affects joints (both small and large joints in asymmetric patterns).Sometimes, Tuberculous arthritis occurs secondary to the extension of underlying TB osteomyelitis of bones involved in joint formation.If aggressive, then earlier spread to other body systems like reticuloendothelial system, etc. Lymphadenopathy and ascites in the above case are signs of secondary dissemination of primary bone TB.However, all signs and symptoms will be settled once ATT has started.