Abstract
Background:
Tuberculosis (TB) is endemic in the sub-saharan Africa (SSA), and up to 70% of adults with TB are infected with Human Immunodeficiency Virus (HIV). In clinical practice, where extra-pulmonary TB (i.e spine) is suspected, treatment is often empirically initiated on clinical and radiological features as access to resources is not always easy. If it looks like TB, is it always TB?
Objective:
To demonstrate that, “if it looks like TB, it might not be TB”.
Design:
Retrospective record-based study.
Methods:
The aim of the study was to audit retrospectively the histology results of all patients who underwent incisional (percutaneous core biopsy) and excisional (radical debridement) of spine, whenever the diagnosis of TB spine was suspected. Data were collected using case sheets of 206 spine patients from the medical records from a newly established orthopaedic spine unit database, as well as histology results from the National Health Laboratories Services. Inclusion criteria were complete medical records and histology results.
Results:
Of 206 patients on the database, between January and December 2013, 46 biopsies were performed.
Only 30 patients met the inclusion criteria. Necrotising granulomatous inflammation was seen in 19 (63.3%) of biopsies; acid fast bacilli (AFB) were present in 6 of the biopsies, and 12 were AFB negative. PCR (Polymerase Chain Reaction) testing was performed on the 12 AFB negative specimens; 5 were positive for Mycobacterium tuberculosis and 1 for Mycobacterium xenopi. The combined positive result for Mycobacterium tuberculosis was 11 (36.6%) specimens.
Of the remaining 11 specimens, 2 were diagnosed as Cryptococcal osteomyelitis, 2 as metastatic adenocarcinoma (lung), and 8 specimens showed no granulomatous inflammation or evidence of malignancy.
Conclusion:
If it looks like TB; it may not be TB as demonstrated in the results. Biopsy is mandatory where TB is suspected. With HIV so prevalent; atypical mycobacterial or non-mycobacterial TB manifestations are possible. And do not forget other possible diagnoses.
