Association between the histological diagnosis of tuberculosis and microbiological findings

Pathology of lymph node tuberculosis in Yaounde: diagnostic agreement based on the Kappa coefficient

Introduction

Lymph node tuberculosis remains widespread in Cameroon. Our goal was to compare the diagnostic agreement between the hematein-eosin coloration technique and the Ziehl-Neelsen technique.

Methods

This study is a retrospective and comparative study realized in the Yaounde University Teaching Hospital over a period of 5 years. We needed to specify the diagnostic agreement for tuberculosis, first inter observer and secondly between the standard and special colorations. The data we collected allowed us to determine the agreement rates observed and the kappa (k) coefficients with linear weighting.

Results

The 186 samples of the 1726 cases of tuberculosis of all locations represented a proportion of 10.78%. There were more male patients (65.05%) with a sex ratio (M:F) of 1.30. The average age was 24.21 ± 15.5 with the extremes from 5 to 68 years. The most represented age group was from 10 to 39 years. The two observers agreed in 93 cases using hematein eosin coloration (P₀ = 83.87 %; k = 0.8109) and on 73 samples using the Ziehl-Neelsen coloration (P₀ = 89.78 %; k = 0.7734). The two coloration techniques presented an agreement on 104 samples (P₀ = 88.17 %; k = 0.8783).

Conclusion

The routine choice of the hematein eosin coloration technique not paired with the coloration technique of Ziehl-Neelsen can effectively alleviate the program for fighting tuberculosis in an environment of limited resources.

The relevance of biopsy in tuberculosis patients without human immunodeficiency virus infection

Although chronic granulomatous inflammation (CGI) with concomitant caseous necrosis (CN) is a characteristic histological feature of tuberculosis (TB), few studies have investigated its frequency or various pathologic findings. The medical records of 227 human immunodeficiency virus (HIV) -negative, culture-positive TB patients who underwent biopsy were studied. After the frequency of characteristic pathological findings of TB was determined, a pathologist reanalyzed the pathological findings with particular focus on necrosis and reclassified CGI, CN, or possible CN into possible TB pathologic findings. The initial biopsy interpretation revealed that 63 (34.8%) of 181 patients with pulmonary TB had caseating granulomas, 36 (19.9%) patients had only CGI, and 6 (3.3%) patients had only CN. Among 46 patients with extrapulmonary TB, 16 (34.8%) patients had only caseating granulomas, and 14 (30.4%) patients had only CGI. More patients who underwent percutaneous lung biopsy had CGI or CN (76.3%) than patients who underwent transbronchial lung biopsy (53.6%). The reanalysis confirmed all CN cases identified by the first interpretation, and 20 (95.2%) of 21 non-CN cases were reclassified as possible CN. Ten cases (three pulmonary and seven extrapulmonary) were reclassified as possible TB pathologic findings from just necrosis. Caseating granuloma was present in only one-third of TB cases. Even in cases where only necrosis was identified, CN may be present.

The relevance of biopsy in tuberculosis patients without human immunodeficiency virus infection

Although chronic granulomatous inflammation (CGI) with concomitant caseous necrosis (CN) is a characteristic histological feature of tuberculosis (TB), few studies have investigated its frequency or various pathologic findings. The medical records of 227 human immunodeficiency virus (HIV) -negative, culture-positive TB patients who underwent biopsy were studied. After the frequency of characteristic pathological findings of TB was determined, a pathologist reanalyzed the pathological findings with particular focus on necrosis and reclassified CGI, CN, or possible CN into possible TB pathologic findings. The initial biopsy interpretation revealed that 63 (34.8%) of 181 patients with pulmonary TB had caseating granulomas, 36 (19.9%) patients had only CGI, and 6 (3.3%) patients had only CN. Among 46 patients with extrapulmonary TB, 16 (34.8%) patients had only caseating granulomas, and 14 (30.4%) patients had only CGI. More patients who underwent percutaneous lung biopsy had CGI or CN (76.3%) than patients who underwent transbronchial lung biopsy (53.6%). The reanalysis confirmed all CN cases identified by the first interpretation, and 20 (95.2%) of 21 non-CN cases were reclassified as possible CN. Ten cases (three pulmonary and seven extrapulmonary) were reclassified as possible TB pathologic findings from just necrosis. Caseating granuloma was present in only one-third of TB cases. Even in cases where only necrosis was identified, CN may be present.

Phage lysin as a substitute for antibiotics to detect Mycobacterium tuberculosis from sputum samples with the BACTEC MGIT 960 system

Phage lysin was evaluated as a substitute for antibiotics in sputum samples processed by a modified Petroff's method for the detection of Mycobacterium tuberculosis with the MGIT 960 system. One hundred and fifty sputum samples were processed, inoculated onto two slopes of Lowenstein-Jensen medium, and divided in to two aliquots of 0.5 mL each. One aliquot was added to 7 mL of MGIT medium containing polymyxin B, amphotericin B, nalidixic acid, trimethoprim and azlocillin (PANTA) (MGIT-PANTA) and the other was added to 7 mL of MGIT medium containing 0.8 mL of lysin (MGIT-Lysin). The samples were randomized and incubated at 37°C in the MGIT 960 system. The sensitivity and specificity of MGIT-Lysin were 97% and 88%, respectively, as compared with MGIT-PANTA. The average times to detection with MGIT-Lysin and MGIT-PANTA were 9.3 and 8.6 days, respectively. The rate of contamination with MGIT-PANTA and MGIT-Lysin were 16% and 7.3%, respectively. Phage lysin can be substituted for antibiotics in processed sputum samples for the detection of M. tuberculosis.

Bilateral parotid swelling caused by sarcoidosis

BACKGROUND

Sarcoidosis is a multisystem granulomatous disease characteristically causing bilateral hilar lymphadenopathy. Salivary gland swellings also are seen, which mandate recognition by the dental profession.

CASE DESCRIPTION

The authors describe a patient whose diagnosis of sarcoidosis was tenuous. Ocular involvement and an elevated serum angiotensin-converting enzyme level suggested a diagnosis of sarcoidosis. Confirmation with a tissue biopsy was achieved only when the clinicians recognized that salivary gland swelling probably represented a manifestation of the disease. Steroid therapy was instituted.

CLINICAL IMPLICATIONS

It is important for the dental practitioner to be familiar with the salivary gland manifestation of sarcoidosis. Early recognition and intervention aborts or slows disease progression.

Tuberculous osteomyelitis of the mandible: a case report

Osteomyelitis of jaws caused by infection with Mycobacterium tuberculosis is uncommon, especially in children. We present a case of tuberculous osteomyelitis in a young child. Its clinical presentation, with features similar to a dento-alveolar abscess, underline the importance of considering it in the differential diagnosis of jaw lesions. We discuss of the diagnostic techniques, management and preventive measures, and stress the importance of history taking during clinical examination.

PCR on disseminated tuberculosis in bone marrow and liver biopsy specimens: correlation to histopathological and clinical diagnosis

Disseminated tuberculosis with negative pulmonary findings is a diagnostic problem. Histopathological studies of bone marrow (BM) and liver (LV) biopsies are the most reliable methods for diagnosis in such cases; however, their sensitivity is limited. In this retrospective study, 41 BM and 7 LV paraffin-embedded biopsy specimens from clinically (clinical response to antituberculous treatment after 6 months follow-up) and/or histopathologically diagnosed tuberculosis were analysed for the detection of Mycobacterium tuberculosis DNA by polymerase chain reaction (PCR). Two different primer sets, one based on the repeated IS6110 sequence of M. tuberculosis and the other based on the mtp40 gene region, were used for amplification. Histopathological and PCR studies were positive for M. tuberculosis in 12/41, and 30/41 in BM and 4/7, and 6/7 in LV biopsy specimens, respectively. As the control group, 17 BM biopsy specimens obtained from patients with a positive Mantoux skin test but no active tuberculosis were analysed. One BM biopsy out of 17 control cases was positive with PCR while none was consistent with TB histopathologically. In conclusion, PCR might be applicable and more reliable than histopathological studies for detection of tuberculosis in BM and LV biopsy specimens.

Oral tuberculosis

Tuberculous lesions of the oral cavity have become so infrequent that it is virtually a forgotten disease entity and may pose a diagnostic problem. Fifteen patients with conditions that were histologically diagnosed as oral tuberculosis were reviewed. All were men ranging in age from 29 to 78 years. The most common clinical presentation was odynophagia with a duration from less than 1 week to several years. The most frequently affected sites were the tongue base and gingiva. The oral lesions took the form of an irregular ulceration or a discrete granular mass. Mandibular bone destruction was evident in two patients. Two patients had a fever, and four had cervical lymphadenopathy. Eight cases were clinically suspicious for malignancy before biopsy. Only four patients had a history of tuberculosis, but 14 of the 15 patients were later found to have active pulmonary tuberculosis. Acid-fast bacilli were demonstrated in all patients. Tuberculosis should be considered in patients with an inflamed ulcer lesion. A biopsy specimen for histologic study, acid-fast stains, and cultures should be obtained for confirmation and differential diagnosis with other conditions. If a tuberculous lesion is suspected, a chest radiograph is indicated to investigate the possibility of pulmonary involvement.

Use of polymerase chain reaction for primary diagnosis of pulmonary tuberculosis in the clinical laboratory

A nested polymerase chain reaction (PCR) has been used for the rapid detection of tubercule bacilli in respiratory specimens from 287 patients suspected of tuberculosis. The results of PCR testing were compared with isolation methods (conventional culture and Bactec system) in 110 smear-positive and 177 smear-negative patients. There were only 4 false negative results by PCR in the 171 specimens that were M. tuberculosis complex culture-positive. Of 92 PCR-positive samples prepared from the smear-positive specimens 90 (97.8%) were confirmed by culture. However, a poor correlation was obtained between initial 122 PCR-positive results and combined 81 culture recovered organisms in smear-negative patients. After verification of the efficacy of isolation method, retesting PCR-positive culture-negative samples, and studies of patients' clinical histories, only 18 of the cases were found to be associated with the disease. The other 29 results out of the original 47 discrepants were considered PCR false positives, possibly due to contamination. In conclusion, the PCR assay described is suitable for implementation in daily routine work with respiratory specimens, however it should be validated with culture, especially for the smear-negative patients.

Hepatobiliary tuberculosis presenting as a gall bladder tumor

A 64-year-old married female was admitted with a presentation of anorexia, easy fatiguability, skin discoloration, tea-colored urine and weight loss of 1 month's duration. After a series of clinical and laboratory examinations including radiological image studies, a diagnosis of gall bladder tumor was presumed. A final diagnosis of tuberculosis of the liver and gall bladder was established by histopathological examination of tissue specimens obtained during exploratory laparotomy. Hepatobiliary tuberculosis presenting as a gall bladder tumor is rare and no pathognomonic diagnostic characteristics can be relied upon. It is necessary to confirm the diagnosis by histopathology, polymerase chain reaction (PCR), or microbiological studies on biopsy specimens in order to make possible appropriate, early therapy.