Tuberculous Osteomyelitis Mimicking a Lytic Bone Tumor: Report of Two Cases and Literature Review

Unifocal Tubercular Osteomyelitis of Ulna Diaphysis in a Child: A Case Report

Introduction

Osteoarticular tuberculosis (OATB) contributes to around 10% of extrapulmonary tuberculosis of which the spine is the most common site. Isolated involvement of ulna diaphysis is extremely rare. We present a case of unifocal tuberculous osteomyelitis of ulna diaphysis in a 3 -year-old male child and highlight its resemblance with musculoskeletal tumors and stress the importance of GeneXpert mycobacterium tuberculosis (MTB)/resistance to rifampicin (RIF) in the diagnosis of OATB.

Case Report

A mother of a 2-year-old male child incidentally noticed that her son complained of left forearm pain. She was not sure of any fall or trauma to the forearm. No history of fever or other constitutional symptoms was present. Clinical examination was uneventful except for local tenderness in over the dorsomedial aspect of the left mid forearm. A plain radiograph revealed an oval solitary lytic lesion over distal one-third ulna diaphysis. A needle biopsy was done after clinical, hematological, and radiological evaluation, and finally, GeneXpert detected tuberculosis without RIF. No further tests were required and the child was started on antitubercular therapy (ATT) which resulted in complete healing without any symptoms.

Conclusion

The authors conclude that it is therefore essential to consider tuberculosis in the differential diagnosis while evaluating a lytic bone lesion. Where possible, all patients should have a biopsy of the lesion and provide a specimen for GeneXpert MTB/RIF to confirm the diagnosis and drug susceptibility testing.

Tumor-mimicking musculoskeletal infectious lesions: Experience of a single referral center

Introduction/Objectives. Bone and soft tissue infections might mimic bone and soft tissue tumors. Therefore, differential diagnosis is important to prevent errors in treatment. This report aims to present the data of patients with indistinct clinical and radiological findings mimicking benign and malignant bone and soft tissue tumors, which were later diagnosed as inflammatory infections. Methods. A retrospective chart review of the clinical, microbiological, radiologic, and pathologic findings of patients presented with a presumed diagnosis of a possible malignant lesion was performed. Results. The study included 21 patients with a median age (IQR) of 37 (1 month ? 72 years) years, and 13 (61%) patients were men. In total, 16 (76%) patients were admitted to the hospital with complaints of pain. The diagnoses were hydatid cyst, tuberculous osteomyelitis, cat-scratch disease, chronic osteomyelitis, subacute osteomyelitis, and soft tissue abscess. All patients were treated depending on the diagnosis of the lesion. Conclusion. There are chances of misdiagnosis due to shared common characteristics of tumoral and infectious lesions which might be mildly increased inflammatory markers with deeply seated non-mobile soft tissue masses and aggressive periosteal reactions and/or bone destruction patterns. So, each pseudotumoral lesion due to possible infectious causes should be histopathologically examined and correlated with other clinical and laboratory data in order to achieve a final diagnosis

Chest Wall Mass in Infancy: The Presentation of Bone-Tumor-Like BCG Osteitis

Chest wall mass in infancy is rare. Malignant lesions are more common than infection or benign tumors. This is a case of a 12-month-old girl who presented with a 2 cm mass at the right costal margin and poor weight gain. Chest radiograph demonstrated a moth-eaten osteolytic lesion at the 8th rib. The resection was performed, and a mass with pus content was found. The positive acid fast stain (AFB) organism was noted. Pathology confirmed caseous granulomatous inflammation compatible with mycobacterial infection. However, QuantiFERON-TB Gold was negative, so Mycobacterium bovis (M. bovis) osteitis is highly suspected. She was treated with antimycobacterium drugs and showed good results. Osteomyelitis can manifest by mimicking bone tumors. Without a biopsy, the pathogen may go undetected. So, interventions such as biopsy are warranted and avoid mass resection without indication. High C-reactive protein (CRP), alkaline phosphatase (ALP), periosteal reaction of radiating spicules, and penumbra sign in magnetic resonance imaging (MRI) are helpful for discriminating osteomyelitis from bone tumor.

Tuberculosis (T.B.) masquerading as tumor. An 8-year study on 25 cases of long bone tuberculosis presenting as tumors

Aim: To highlight radiological features and emphasize the need for tissue diagnoses to confirm bone pathology. Tuberculosis is known to present without constitutional symptoms and with unconventional imaging features mimicking sarcomas as shown in our series of 25 patients; where the imaging and biopsy protocols at our institute helped to solve these diagnostic dilemmas. Material and methods: We retrospectively analyzed clinical and radiological features and tissue diagnoses in 25 patients referred to the department of orthopedic oncology with radiological suspicion of tumor. Results: Only 7 patients had cultures positive for Mycobacterium Tuberculosis T.B. Radiological features suggestive of infection were Metaphyseal and joint involvement, permeative lesions, absence of Codman’s triangle, and soft tissue mass suggestive of a cold abscess. The predictive accuracy of the orthopedic oncologist was 60% and musculoskeletal radiologist was 72% (based on radiology). Final diagnosis is 100% confirmed on histopathology. Conclusion: Diagnosis based primarily upon imaging is a wrong approach. A multimodal approach to differentiating tuberculous bone infections from sarcomas is essential.