Role of fine-needle aspiration cytology in tuberculosis of bone

Imaging of musculoskeletal tuberculosis

Tuberculosis (TB) represents a major public health problem worldwide. Any tissue may be infected. Involvement of the musculoskeletal (MSK) system account for 1-3% of all tuberculous infections. MSK TB may manifest as tuberculous spondylitis, arthritis, osteomyelitis, and soft tissue infections. Although TB spondylitis may present with distinctive imaging features compared to pyogenic infections of the spine, the imaging semiology of extra-spinal TB infections is mostly nonspecific and may mimic other lesions. TB infections should therefore always be considered in the differential diagnosis, particularly in immunocompromised patients. The aim of this article is to review the imaging features of spinal and extra-spinal MSK TB. Magnetic resonance imaging is considered the modality of choice to make the diagnosis and to evaluate the extent of the disease.

Osteoarticular tuberculosis: A series of six cases diagnosed on fine-needle aspiration cytology

A few studies are dealing with the role of fine-needle aspiration cytology in diagnosing osteoarticular tuberculosis (TB). The present study was undertaken to study the cytomorphological features of six cases of osteoarticular TB throughout 1 year, diagnosed by fine-needle aspiration cytology. The Papanicolaou, Giemsa, Ziehl–Neelsen, and periodic acid–Schiff stains were used in each case. The sampled material was also cultured in Lowenstein– Jensen media for Mycobacterium species and polymerase chain reaction assay for Mycobacterium tuberculosis. Histopathological findings were correlated whenever available. There were four male and two female patients. The age of the patients ranged from 15 to 53 years, with a mean age of 37 years. Most cases involved small bones (4/6) and long bones of upper and lower limbs (2/6). Radiologically, the suspected lesions presented as osteolytic lesions, fractures, and joint destruction. The smears showed epithelioid cell granulomas in 5 out of 6 cases (83.3%), multinucleate and Langhans’ giant cells in 3 out of 6 cases (50%), and only necrosis in 1 case (16.7%). Inflammatory cells were seen in the background in 5 out of 6 cases (83.3%). AFB was positive in 3 cases (50%). Culture in Löwenstein–Jensen media, done in three cases, showed growth of M. tuberculosis. PCR showed positivity for M. tuberculosis in all six cases. Fine-needle aspiration cytology is an easy procedure that can be used for the diagnosis of osteoarticular tuberculosis. Cytomorphologically, smears show epithelioid cell granulomas, multinucleated and Langhan’s’ giant cells, and necrosis.

Tuberculosis-Specific Antigen/Phytohemagglutinin Ratio Combined With GeneXpert MTB/RIF for Early Diagnosis of Spinal Tuberculosis: A Prospective Cohort Study

Spinal tuberculosis (TB), the most common form of musculoskeletal tuberculosis, is an infection-related disease globally, with paraplegia occurring in severe cases. Therefore, identification of spinal TB at an early stage is important for early intervention and eventual therapy. In this study, we conducted a prospective cohort study in routine clinical practice to investigate the diagnosis of different TB tests. A total of 519 patients were recruited based on the radiology of spinal TB. The diagnostic model was computed by regression analysis and was determined by receiver operating characteristic (ROC) curve analysis. Specificity, sensitivity, predictive value, likelihood ratio, and accuracy were also computed and compared. GeneXpert MTB/RIF showed a higher positive rate compared to that in the acid-fast bacilli smear and Mycobacterium culture. The results also showed that the Mycobacterium tuberculosis-specific antigen/phytohemagglutinin ratio in the T-SPOT assay had a good performance in the preoperative diagnosis and prediction of spinal TB. The diagnostic model based on the ratio of tuberculosis-specific antigen/phytohemagglutinin combined with GeneXpert MTB/RIF showed better efficiency for spinal TB diagnosis. In summary, the tuberculosis-specific antigen/phytohemagglutinin ratio combined with GeneXpert MTB/RIF could provide an early diagnosis of spinal TB.

A rare lumbar pyogenic spondylodiscitis caused by staphylococcus caprae with initial misdiagnosis: case report and literature review

Background

Staphylococcus caprae (Sc) is an uncommon causative organism for human. Lumbar pyogenic spondylodiscitis (LPS) of Sc is extremely rare and only a few cases have been reported. As far as we know, there is no specific literature on the diagnosis and treatment for LPS of Sc with L5 nerve root irritation.

Case presentation

A 65-year-old male patient complained of chronic low back pain for 10 years, acute worsening with radiating pain to left lower extremity over a month. Physical examination revealed tenderness point on his low back, 3/5 dorsiflexor strength in his left 1st toe and decreased sensation of pin prick over the left lateral shank and medial dorsal foot. The individual was initially misdiagnosed with lumbar disc herniation (LDH) without further examination in outpatient, which was then found to be LPS of Sc with L5 nerve root irritation after admission to our hospital. Magnetic resonance images (MRI) of lumbar spine exhibited inflammation signal at L4-L5 level of the vertebral body and disc with hypointense on T1-weighted images (T1-WI) and hyperintense on T2-weighted images (T2-WI). The causative organism was confirmed by the culture of irrigation fluid obtained from L5 vertebrae by needle puncture. After systemic conservative treatment including using sensitive antimicrobial agents and immobilization, the rare infection was finally cured. The patient also showed a satisfactory recovery during the 36-month follow-up period.

Conclusions

Confirming the diagnosis and identifying the causative organism as soon as possible is the key point for the treatment of LPS. LPS of Sc causing nerve root irritation is rare but curable with early diagnosis and proper therapy. The culture of irrigation fluid obtained from vertebrae by needle puncture may be an effective and sensitive attempt for potential infection of spine to identify the causative organism at early stage of the disease.

Tuberculosis of lunate as an isolated intraosseous osteolytic lesion in an adult: a diagnostic challenge

In an endemic zone of tuberculosis (TB), osseous involvement is a relatively common presentation. Spine and long bones are the the most common nidus of TB. Smaller bones and joints are relatively less involved. Thorough clinical examination and history of typical constitutional symptoms like weight loss, fever and loss of appetite are the diagnostic aids for initiating early treatment. Wrist and hand involvement is a rare occurrence and often presents atypically without any obvious symptoms or signs. This results in delayed diagnosis and worse outcome. TB of lunate without articular involvement is a very rare subset and we present such an isolated case of TB involving the lunate, without any typical symptoms, with the patient complaining of vague pain without any restriction of joint mobility. TB was diagnosed with the aid of radiology, haematology and histopathology. 18 months of multidrug antitubercular treatment was given, to which the patient responded well.

Extensive Paraspinal Tuberculosis Masquerading Malignant Tumor in an Elderly Male

Paraspinal tuberculosis is an uncommon manifestation of extrapulmonary tuberculosis, and in rare cases, these lesions can mimic malignant lesions. We report a case of an elderly man where imaging showed extensive left paraspinal lesion which was mimicking malignant neoplasm. The patient underwent L3–L4 unilateral partial laminotomy, there was grayish, relatively avascular lesion in the left paraspinal region, involving the left psoas muscle and going into the neural foramina, and a subtotal resection of the lesion could be performed. However, after biopsy, it turned out to be tuberculoma, and the patient was on antitubercular therapy and doing well. The present case illustrates that extensive involvement of the paraspinal soft tissue and adjacent bony structures on imaging in tuberculosis can mimic malignant tumors. Conservative surgical excision will help in preserving the bony elements and in establishing the diagnosis.

Musculoskeletal Tuberculosis

Musculoskeletal tuberculosis (TB) accounts for approximately 10% of all extrapulmonary TB cases in the United States and is the third most common site of extrapulmonary TB after pleural and lymphatic disease. Vertebral involvement (tuberculous spondylitis, or Pott's disease) is the most common type of skeletal TB, accounting for about half of all cases of musculoskeletal TB. The presentation of musculoskeletal TB may be insidious over a long period and the diagnosis may be elusive and delayed, as TB may not be the initial consideration in the differential diagnosis. Concomitant pulmonary involvement may not be present, thus confusing the diagnosis even further. Early diagnosis of bone and joint disease is important to minimize the risk of deformity and enhance outcome. The introduction of newer imaging modalities, including MRI (imaging procedure of choice) and CT, has enhanced the diagnostic evaluation of patients with musculoskeletal TB and for directed biopsies of affected areas of the musculoskeletal system. Obtaining appropriate specimens for culture and other diagnostic tests is essential to establish a definitive diagnosis and recover M. tuberculosis for susceptibility testing. A total of 6 to 9 months of a rifampin-based regimen, like treatment of pulmonary TB, is recommended for the treatment of drug susceptible musculoskeletal disease. Randomized trials of tuberculous spondylitis have demonstrated that such regimens are efficacious. These data and those from the treatment of pulmonary TB have been extrapolated to form the basis of treatment regimen recommendations for other forms of musculoskeletal TB.

Multiple Bony Metastatic Lesions and Evaluation of Primary: Case Records of a Cancer Research Centre

During 2012-13, we diagnosed 4 patients with extensive skeletal tuberculosis (TB) who were referred to us as cases of bony metastasis with unknown primary. Radiological investigations done outside favoured a diagnosis of disseminated malignancy. Positron emission tomography/computed tomography (PET/CT) scan performed in our institute for localization of primary lesion also suggested metastatic disease. There was no evidence of malignancy on histo-pathological examination (HPE) of the involved sites. The diagnosis of TB was established on characteristics HPE. This article highlights the diagnostic dilemma of PET/CT in cases of TB versus malignancy and the importance of HPE for reaching an accurate diagnosis.

Correlation of eosinophilic structures with detection of acid-fast bacilli in fine needle aspiration smears from tuberculous lymph nodes: Is eosinophilic structure the missing link in spectrum of tuberculous lesion?

Background:

Acid-fast bacilli (AFB) is not seen in all necrotic tuberculous lesions. If the subset of tuberculous lesions which yield positive result for AFB can be identified, it would save on time and manpower besides optimizing use of resources. A prospective study was undertaken to assess if presence of eosinophilic structures (ESs) in necrotic tuberculous lesions correlated with the presence of AFB.

Materials and Methods:

Patients referred for fine needle aspiration cytology for evaluation of lymphadenopathy between July 2012 and June 2013 were analyzed. The hematoxylin and eosin and May-Grünwald-Giemsa stained slides were screened for epithelioid cell granuloma, ES and necrosis and Ziehl Neelsen stained smears for AFB.

Result:

One hundred and eight tuberculous lymph nodes yielded necrotic material on aspiration. Four cytologic pictures were seen: (a) ES⁺ AFB⁺ in 58.33%, (b) ES⁺ AFB⁻ in 20.37%, (c) ES⁻ AFB⁺ in 9.26% (d) ES⁻ AFB⁻ in 12.04% cases. Overall AFB was found in 67.59% cases, out of which 58.33% correlated with the presence of ES while 9.26% were seen in smears without ES.

Conclusion:

Presence of ESs should be included in the morphological description of tuberculous lesions. In the absence of granulomas, they indicate tuberculous nature of the lesion. Presence of ES mandates a search for AFB as probability of finding AFB is high in such lesions. Significance of ES lies in their presence and not in their absence. Eosinophilic structures appear to be the missing link in the spectrum of tuberculous lesion.

A child presenting with tuberculous spondylitis in a single third cervical vertebra: a case report

INTRODUCTION

Despite a global reduction in tuberculosis, extrapulmonary tuberculosis is increasing. Spinal tuberculosis remains the commonest form of skeletal tuberculosis. Cervical spine involvement is rare but is the most dangerous form because of diagnostic difficulties and serious residual disability. We report a child who had single vertebral involvement of her third cervical vertebra which is extremely rare. To the best of our knowledge isolated third cervical vertebra involvement in a child by tuberculosis has not been reported previously. Difficulties in obtaining material for histology and bacterial culture from this critical location and how the diagnosis was reached despite these challenges are highlighted.

CASE PRESENTATION

A 10-year-old Sinhalese girl developed painful torticollis and 'cries during sleep'. She had received Bacillus Calmette-Guérin vaccine at birth, was well nourished, and had no loss of weight, anorexia or contact with tuberculosis. A plain radiograph of her neck showed a collapsed third cervical vertebra with no disc involvement. Magnetic resonance imaging confirmed isolated destruction of third cervical vertebra associated with prevertebral soft tissue swelling indenting the thecal sac without cord compression. Her chest radiograph was normal. There was peripheral lymphocytosis, elevated erythrocyte sedimentation rate, negative tuberculin (Mantoux) test, and negative QuantiFERON®-TB GoldIn-Tube assay. Invasive procedures to obtain tissue for histology, smear or culture were perceived by parents as dangerous due to surrounding critical structures and consent was denied. The differential diagnosis included spinal tuberculosis and unifocal Langerhan cell histiocytosis. Nocturnal symptoms and the prevertebral collection of soft tissue ('cold abscess') were characteristic of tuberculosis, and nonspecific findings of elevated erythrocyte sedimentation rate and lymphocytosis supported this diagnosis. An incidental finding of a calcified hepatic nodule when evaluating for multifocal histiocytosis was presumed to be tuberculous because schistosomiasis and visceral leishmaniasis were extremely rare in her country of residence, Sri Lanka. Empirical treatment with a 12-month course of antitubercular therapy resulted in clinical recovery and radiological healing. There was no kyphosis or neurological sequel.

CONCLUSIONS

This report highlights to clinicians the value of a high index of suspicion and careful history taking in spinal tuberculosis; and how a combination of nonspecific findings helped reach a clinicoradiological diagnosis.

Spinal tuberculosis: a review

Spinal tuberculosis is a destructive form of tuberculosis. It accounts for approximately half of all cases of musculoskeletal tuberculosis. Spinal tuberculosis is more common in children and young adults. The incidence of spinal tuberculosis is increasing in developed nations. Genetic susceptibility to spinal tuberculosis has recently been demonstrated. Characteristically, there is destruction of the intervertebral disk space and the adjacent vertebral bodies, collapse of the spinal elements, and anterior wedging leading to kyphosis and gibbus formation. The thoracic region of vertebral column is most frequently affected. Formation of a 'cold' abscess around the lesion is another characteristic feature. The incidence of multi-level noncontiguous vertebral tuberculosis occurs more frequently than previously recognized. Common clinical manifestations include constitutional symptoms, back pain, spinal tenderness, paraplegia, and spinal deformities. For the diagnosis of spinal tuberculosis magnetic resonance imaging is more sensitive imaging technique than x-ray and more specific than computed tomography. Magnetic resonance imaging frequently demonstrates involvement of the vertebral bodies on either side of the disk, disk destruction, cold abscess, vertebral collapse, and presence of vertebral column deformities. Neuroimaging-guided needle biopsy from the affected site in the center of the vertebral body is the gold standard technique for early histopathological diagnosis. Antituberculous treatment remains the cornerstone of treatment. Surgery may be required in selected cases, e.g. large abscess formation, severe kyphosis, an evolving neurological deficit, or lack of response to medical treatment. With early diagnosis and early treatment, prognosis is generally good.