Ziehl-Neelsen Stain For Acid-fast Bacilli Research Articles

Utility of a Clinical Scoring System (Bandim TB Score and Karnofsky Performance Score) to Assess Mycobacterial Burden in Terms of Cartridge-Based Nucleic Acid Amplification Test (CBNAAT) Cycle Threshold Values Among Pulmonary TB Patients.

Tuberculosis (TB) continues to be a global public health problem. Physicians fail to clearly interpret cycle threshold (Ct)values as a measure of mycobacterial burden due to the paucity of literature correlating Ct values with the clinical scoring. This study aims to correlate the clinical scoring parameters (Bandim TB scoreand Karnofsky Performance score (KPS)) with Ct values obtained by Cartridge-Based Nucleic Acid Amplification Test (CBNAAT). The study spanned from November 2019 to October 2021, during which a total of 40 cases were recruited. These cases were identified as pulmonary TB patients based on Ziehl-Neelsen staining for acid-fast bacilli and/or the GeneXpert MTB/RIF assay. Bandim TB scores and KPSs were recorded using standardized questionnaires. There was a strong negative correlation between Bandim TB score and Ct value (mean), and this correlation was statistically significant (rho = -0.82, p < 0.001). There was a moderate positive correlation between KPS and Ct value (mean), and this correlation was statistically significant (rho = 0.57, p < 0.001). No literature has compared Bandim TB score and KPS with the Ct values obtained by CBNAAT for pulmonary TB. Thus, the knowledge on the proper utilization of CBNAAT cycle threshold values and its correlation with clinical scoring parameters will help clinicians in the early identification and prompt initiation of appropriate treatment.

SAT612 Granulomatous Mastitis: An Unusual Presentation Of Prolactinoma

Abstract Disclosure: H.R. Alkaissi: None. E. Kim: None. S. McFarlane: None. Background: Granulomatous mastitis (GM) is a rare, benign inflammatory breast disease of unclear etiology with clinical presentation that is similar to inflammatory breast cancer and periductal lobular mastitis. It occurs mainly in younger females and during the postpartum period. Prolactin (PRL) is an essential hormone of pituitary and extrapituitary origin that promotes lactation and the development of mammary glands within breast tissues. In addition to its lactogenic effect, it has over 300 other effects, several of which are immunomodulatory, including the expression and secretion of proinflammatory cytokines from macrophages. Clinical Case: A 37-year-old African American woman presented with right breast pain and swelling for a few weeks. Her medical history includes amenorrhea for five years. She is gravida 1, para 1 with normal spontaneous vaginal delivery at the age of 20. Physical exam showed non-bloody, non-purulent nipple discharge bilaterally, otherwise unremarkable. A breast ultrasound showed a 1 cm complex cystic mass. Biopsy showed benign breast tissue, with noncaseating granulomas formed by macrophages (CD68 positive on immunohistochemistry). Ziehl-Neelsen staining for acid-fast bacilli was negative. Staining for fungi was also negative. Prolactin level was 237 ng/mL. TSH, IGF-1, and ACTH were within normal. Pituitary MRI showed a focus of abnormal signal and diminished enhancement measuring 2.8x3.2x4.2 mm within the left side of the pituitary gland is compatible with a microadenoma. The patient was started on bromocriptine 2.5mg daily. Discussion: Our patient represents a rare case of granulomatous mastitis in the setting of microprolactinoma, likely long-standing, given the five years history of amenorrhea. The immunomodulatory effect of PRL on several immune system cells, including B-cells, T-cells, and macrophages, might be an underlying mechanism. In a recent study of 25 samples of GM, metagenomics studies identified unusual organisms in 68% of the samples. Of these, Corynebacterium kroppenstedtii was the most common (60%), followed by Pseudomonas oleovorans (16%), Epstein-Barr virus (4%), Acinetobacter baumannii (4%), and Tepidiphilus thermophilus (4%). In addition, 50% of the patients had elevated PRL, and elevated immunological markers, such as C3 and IgA [1]. This suggests that GM results from an interaction between the presence of certain pathogens in a host with elevated PRL that mediates proinflammatory response.

Assessing Pulmonary Tuberculosis Using Bandim Tuberculosis and Karnofsky Performance Scale Scores with Serum Adenosine Deaminase Levels.

Elevated pulmonary serum adenosine deaminase (ADA) levels signify lung tissue damage and severe tuberculosis (TB). Serum ADA assays can be used as an additional criterion for assessing TB treatment response and as a prognostic marker in patients with pulmonary TB. The Bandim TB and Karnofsky Performance Scale (KPS) scores were developed based on available clinical data and investigations to allow physicians to evaluate disease treatment and response. This study examined the use of a clinical scoring system (Bandim TB and KPS scores) in the context of serum ADA activity. Forty adults (aged >18 years) diagnosed with pulmonary TB by Ziehl-Neelsen staining for acid-fast bacilli and/or cartridge-based nucleic acid amplification test were recruited. Standardized questionnaires were used to record Bandim TB and KPS scores. Serum ADA levels were estimated using a commercial kit. The Bandim TB score was positively associated (ρ=0.74, P≤0.001) and the KPS score was negatively associated (ρ=-0.69, P≤0.001) with serum ADA levels. Subjective and objective clinical scores of pulmonary TB were strongly correlated with serum ADA levels. Knowledge of clinical scores corresponding to serum ADA levels could help physicians understand stage and progression of the disease which may aid in early detection and better management, and reduce disease transmission in a TB-endemic country.

Fine-needle aspiration cytology of Bacille Calmette-Guerin adenitis: A perplexing distinct clinical entity.

Bacille Calmette-Guerin (BCG) adenitis is a common complication of post-BCG vaccination. Awareness of this lesser known entity in fine-needle aspiration (FNA) is important to prevent misdiagnosis. This study described the clinical presentation, cytomorphological features and disease pattern in patients with BCG adenitis. We analyzed a series of 15 patients with BCG adenitis seen from July 2017 to July 2019. The detailed clinical and cytomorphology of these cases were studied. Age of presentation ranged from 3 to 12 months. Male to female ratio was 2.75:1. A total of four children were diagnosed with primary immunodeficiency. Three children had acyanotic heart disease. Most of the children had left axillary lymph node enlargement. Cytomorphology showed the presence of polymorphs (66.7%), histiocytic aggregates (80%) and reactive lymphoid population (60%). Epithelioid granulomas (26.7%) and giant cells (6.7%) were present. The necrotic background was present in all but one case. Ziehl-Neelsen stain for acid-fast bacilli was positive in all but two cases. A high index of clinical suspicion for BCG lymphadenitis should be kept in mind for patients who are recently vaccinated. FNA cytology, combined with clinical correlation, is useful for diagnosis and management.

Role of CT Chest and Cytology in Differentiating Tuberculosis from Presumed Sarcoidosis in Uveitis

ABSTRACTPurpose: To report the role of CT chest and cytology in suspected tubercular and sarcoid uveitis.Methods: This is a retrospective, interventional case series of 376 uveitis patients with suspected ocular tuberculosis (TB)/sarcoidosis seen between January 2010 and April 2015 at the Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh. All underwent CT chest, and had following inclusion criteria: (1) Presence of active granulomatous anterior/intermediate/posterior uveitis or panuveitis; (2) a documented tuberculin skin test/QuantiFERON-TB Gold test; (3) all other causes of infectious/non-infectious uveitis ruled out. A total of 206 patients had abnormal CT chest, of which 147 patients with minimum four months follow up were studied. Based on CT findings and amenability of involved lymph nodes, conventional transbronchial needle aspiration (TBNA)/endobronchial ultrasoundguided TBNA (EBUS-TBNA) or fine needle aspiration cytology (FNAC) of peripheral nodes was performed by an interventional pulmonologist. All smears were subjected to cytopathological examination, and Ziehl-Neelsen staining for acid-fast bacilli (AFB). The detection of the underlying etiology (TB or sarcoidosis) was the main outcome measure.Results: CT chest demonstrated mediastinal/hilar lymph nodes in 123/147 (83.7%) patients. Twenty four (16.2%) patients with parenchymal involvement were diagnosed TB (n = 20) or sarcoidosis (n = 4). Sixty nine patients with subcentimetric lymph nodes that were not amenable to biopsy were diagnosed clinico-radiologically as TB (42) and sarcoidosis (27).Fifty-four patients underwent biopsy from various sites that diagnosed TB and sarcoidosis in 21 (38.2%) patients each. Five TBLB/EBUS TBNA smears and seven FNAC smears demonstrated AFB.Conclusions: In systemically asymptomatic individuals presenting with uveitis, CT chest helped to establish the diagnosis of TB/sarcoidosis in 71.43% cases (105 out of 147) using only the clinico-radiological criteria, while a confirmed diagnosis of TB/sarcoidosis was possible only in 42 cases (28.57%) by EBUS/TBNA guided cytological examination.

Bacille Calmette–Guerin lymphadenitis in infants: A lesser known entity – Report of two cases

Bacille Calmette–Guerin (BCG) vaccine containing live-attenuated Mycobacterium bovis was first used in humans to prevent tuberculosis (TB) in 1921. Intradermal BCG vaccine gives rise to classic primary complex that consists of a cutaneous nodule at the site of injection and subclinical involvement of the regional lymph nodes, which is self-limiting and requires no treatment. BCG lymphadenitis is the most common complication of BCG vaccination. Fine-needle aspiration is the rapid, safe, and cost-effective method for diagnosis as well as the management of BCG lymphadenitis. Awareness of this lesser known entity is important to prevent misdiagnosis. We report two cases of 2½ month and 6-month healthy male infants with left axillary lymphadenopathy following BCG vaccination. Fine-needle aspiration from both the cases revealed features of necrotizing granulomatous lymphadenitis with Ziehl-Neelsen stain for acid-fast bacilli being positive in 2nd case. Ipsilateral regional lymph node enlargement following BCG vaccination is considered as the most common complication, some progress to suppuration. Very rarely disseminated BCG infection may develop in immune-compromised individuals, resulting in a devastating outcome. Variable strategies have been applied in treating lymphadenitis related to BCG vaccine in the past decade, ranging from observation, antimycobacterial therapy, aspiration, incision, and drainage to lymph node surgical excision.

Significance of IFN-ɤ/IL-2 Ratio as a Circulating Diagnostic Biomarker in Extrapulmonary Tuberculosis.

Extrapulmonary tuberculosis (EPTB) remains a challenging diagnosis both for clinicians and microbiologists. We hypothesized that the profile of IFN-ɤ/IL-2 ratio in clinically diagnosed cases of EPTB would be distinct from that of age- and sex-matched healthy controls. Therefore, in our study, we have assessed the ratio of serum levels of IFN-ɤ and IL-2 in clinically diagnosed cases of EPTB to assess their potential role as diagnostic biomarkers. Sixty-nine (69) clinically confirmed EPTB cases and 69 age- and sex-matched healthy controls were included in the study. All the extrapulmonary specimens were subjected to Ziehl-Neelsen staining for acid-fast bacilli and culture on Lowenstein-Jensen (LJ) medium. Detection of serum levels of IFN-ɤ and IL-2 was carried out using commercially available ELISA kits following manufacturers' instructions. The ratio of serum levels of IFN-ɤ and IFN-ɤ/IL-2 was discriminative for the diagnosis of EPTB cases (p<0.001), although the same was not observed with IL-2 (p>0.05). Distribution of all biomarkers significantly differed between culture-positive and culture-negative cases (p<0.05). Among the smear-positive and smear-negative ones, only IFN-ɤ and IFN-ɤ/IL-2 ratio could significantly differentiate (p<0.05). Ratio of IFN-ɤ and IL-2 rather than the individual levels was the best discriminatory biomarker with the highest area under the ROC curve. Although IFN-ɤ and IFN-ɤ/ IL-2 ratio could aid in the diagnosis of EPTB, IL-2 has a limited utility in the diagnosis of EPTB. Further elaborate studies to validate these results are required.

Microscopy for Acid Fast Bacilli: A Useful but Neglected Tool in Routine Laboratory Diagnosis of Buruli Ulcer

Background: Laboratory diagnosis of Buruli ulcer disease has become vital with the introduction of antibiotic treatment. Polymerase chain reaction (PCR) for the IS2404 repeat sequence of Mycobacterium ulcerans is the gold standard for laboratory diagnosis. This is expensive and only carried out in reference laboratories in endemic countries in Africa. In order to improve the efficiency of diagnosis at the point of care and reduce the total cost of patient management, we decided to evaluate Ziehl-Neelsen (ZN) staining for acid-fast bacilli (AFB) as an inexpensive diagnostic tool. Methods: Two smears directly prepared at the point of care were examined under oil-immersion microscopy after ZN staining for AFB and compared the results to PCR samples from the same patients. Results: Good quality smears were obtained from all subjects and our results showed that when a second smear was added the sensitivity of microscopy for AFB was increased from 52 to 55% for FNA samples and from 51 to 57 % for swabs. Conclusion: If PCR were to be omitted in all patients with suspected Buruli ulcer disease when AFB were detected it would result in a considerable saving.

Comparison of fine-needle aspiration technique with Ziehl-Neelsen stains in diagnosis of tuberculous lymphadenitis

Background: Lymphadenopathy is one of the most common clinical presentation among patients. In developing countries such as India, tuberculous (TB) lymphadenitis is one of the common causes of lymphadenopathy. Cytomorphology with acid-fast staining is a valuable diagnostic tool in cases of tuberculosis. Objective: To describe pattern of TB lymphadenitis presentation, and to compare results of fine needle aspiration cytology (FNAC) and Ziehl–Neelsen (ZN) stain in the diagnosis of TB lymphadenitis. Materials and Methods: Total 351 patients of lymphadenopathy referred to the Department of Pathology, GMERS Medical College & Hospital, Vadodara, Gujarat, India, between March 2011 and December 2013included. FNAC was performed in all these patients and smears were prepared. Smears were stained with hematoxylin and eosin stain. ZN staining for acid-fast bacilli (AFB) was carried out on separate slide. Results: Maximum number of patients (162; 46.15%) were from age group of 11–30 years. Total 351 cases [179 (50.99%) females and 172 (49.00%) males] were included in the study. Of 351 cases, 173 (49.28%) had tuberculosis, 141 (40.17%) had lymphadenitis other than tuberculosis, and 37 (10.54%) had malignant lymphadenopathy, including 2 (0.56%) cases of primary malignancy (i.e., lymphoma) and 35 (09.97%) of metastasis to lymph nodes. Overall, 119 (33.90%) cases were found to be positive for AFB on ZN staining. Conclusion: FNAC is an optimally selected, efficient, easy to perform, and economical test for initial diagnostic workup in patients with TB lymphadenitis. Supplementation of ZN stain with FNAC increases the rates of diagnosis.

Treatment monitoring with 18F-FDG PET/CT in a patient with peritoneal tuberculosis

A 71-year-old man with a history of spinocellular carcinoma of the right cheek presented with a 2-month history of mild abdominal pain and persistent slight fever. Blood sampling data showed signs of inflammation (C-reactive protein 6.78 mg/ml). Tumour marker levels were normal. Abdominal ultrasonography showed a small amount of perihepatic and pelvic free fluid, increased mesenteric echogenicity and mesenteric lymphadenopathy. 18 F-FDG PET/CT showed increased tracer accumulation in the entire abdominal region (a), associated with the peritoneum and diaphragm (b). CT revealed uniform thickening of the peritoneum (c). Lung findings were unremarkable. Testing of the ascites fluid for acid-resistant bacilli performed twice was negative. Cytological examination revealed mesothelial hyperplasia with inflammatory changes. Diagnostic laparoscopy showed multiple nodules spread throughout the peritoneum. Histology revealed caseating granulomas with epithelioid and Langerhans-type giant cells. Ziehl-Neelsen staining for acid-fast bacilli was negative, but culture of the peritoneal specimen revealed Mycobacterium tuberculosis which resulted in a final diagnosis of peritoneal tuberculosis (PT). The patient’s fever and abdominal pain gradually decreased during antituberculosis treatment. After 6 months of therapy, 18 F-FDG PET/CT showed diminished peritoneal uptake (d) and peritoneal thickening. This case indicates the clinical utility of 18 F-FDG PET/CT for detection

Fine-needle aspiration for diagnosis of tuberculous lymphadenitis in children in Bangui, Central African Republic

BackgroundTuberculosis (TB) is a major cause of childhood morbidity and mortality in developing countries. One of the main difficulties is obtaining adequate specimens for bacteriological confirmation of the disease in children.The aim of this study is to evaluate the adequacy of fine-needle aspiration (FNA) for the diagnosis of TB.MethodsIn a prospective study conducted at the paediatric hospital in Bangui in 2007–2009, we used fine-needle aspiration to obtain samples for diagnosis of TB from 131 children aged 0–17 years with persistent lymphadenitis.ResultsFine-needle aspiration provided samples that could be used for bacteriological confirmation of TB. Ziehl-Neelsen staining for acid-fast bacilli was positive in 42.7% of samples, and culture identified TB in 67.2% of cases. Of 75 samples that were stain-negative, 49 (65.3%) were culture-positive, while 12 stain-positive samples remained culture-negative. Ten of the 12 stain-positive, culture-negative samples were from patients who had received previous antimicrobial therapy. With regard to phenotypic drug susceptibility, 81/88 strains (91.1%) were fully susceptible to isoniazid, rifampicin, ethambutol and streptomycin, six (6.8%) were resistant to one drug, and one multidrug-resistant strain was found.ConclusionsFine-needle aspiration is simple, cost-effective and non-invasive and can be performed by trained staff. Combined with rapid molecular diagnostic tests, fine-needle aspirates could improve the diagnosis of TB and provide valuable information for appropriate treatment and drug resistance.

Ascites as a Presenting Sign of Disseminated Tuberculosis in an Immunocompetent Patient

Purpose: A 39 year-old black male presented with a two-month history of abdominal distension, weight loss (28 Kg), anorexia and fever. On physical examination he was found to have ascites and hepatomegaly. A paracentesis was performed revealing an exsudate with elevated adenosine deaminase (259 U/L). He also had anemia (hemoglobin 11.6 g/dL); high erythrocyte sedimentation rate (45 mm/hr), aspartate aminotransferase (155 U/L), alanine transaminase (106 U/L), alkaline phosphatase (732 U/L), ADA (144 U/L) and elevated C-reactive protein (116 mg/L) levels. Human immunodeficiency virus (HIV) 1 and 2, Hepatitis A, B and C serologies were negative. A thoracic abdomino-pelvic computed tomography (CT) scan showed epiploic adipose densification suggesting peritoneal inflammatory features or peritoneal carcinomatosis and bilateral micronodular pattern in the pulmonary intersticium. Polymerase chain reaction (PCR) for Mycobacterium tuberculosis and Ziehl-Neelsen stain for acid-fast bacilli in the peritoneal fluid, bronchoalveolar lavage (BAL), and urine (3 samples) were negative. Blood cultures were negative. Laparoscopy was performed, with absence of macroscopic peritoneal carcinomatosis and hepatic, intestinal and peritoneal biopsies were retrieved. Histology showed epithelioid hepatic granulomas and peritoneal granulomas with central necrosis. Antituberculous therapy were started (isoniazid, rifampicin, pyrazinamide, and ethambutol), although there has no laboratory confirmation of mycobacterial infection. The cultures from the peritoneal fluid, BAL, and urine were positive. He was discharged with no symptoms and with early recovery, under antituberculous therapy for disseminated tuberculosis (hepatic, renal, peritoneal and pulmonary). Workup for HIV was negative; immunoglobulin levels, lymphocyte subsets, and complement levels were normal. Disseminated tuberculosis is rare, particularly in immunocompetent host and is secondary to hematogenic dissemination of Mycobacterium tuberculosis. The estimated frequency is 2.8% of all cases of tuberculosis and 7.3% of extrapulmonar cases. Predisposing factors for the development of disseminated tuberculosis include advanced age, alcoholism, immunosuppressive therapy, neoplasm, hematologic malignancy or HIV infection. Our patient did not have any of these conditions.

Recurrent Fluctuant Mass of the Wrist and Forearm Associated with Chronic Tenosynovitis by Mycobacterium kansasii

This article presents a case of a painless fluctuant mass on the volar aspect of the wrist and forearm of an immunocompetent 45-year-old man with no history of significant underlying disease. This mass proved to be a chronic tenosynovitis associated with Mycobacterium kansasii infection. The patient, who had a history of multiple minor cuts and abrasions plus exposure to an aquatic environment, had a wide resection of the lesion and elective tenosynovectomy. Operative findings revealed a marked tenosynovitis of flexor tendons. Several rice bodies lesions were also observed along the course of the involved flexor tendons.Biopsy showed a granulomatous inflammatory reaction. Specimens of affected tissue were sent to a laboratory for solid (at 30°C and at 37°C) and liquid (at 37°C) mycobacterial culture. The initial Ziehl-Neelsen stain for acid-fast bacilli was positive. After 8 days of incubation, acid-fast bacilli were recovered. In accordance with the diagnosis of M kansasii tenosynovitis and the results of antibiotic susceptibility testing, triple therapy with rifampicin, isoniazid and clarithromycin was initiated. After 3 months of therapy, the patient experienced improvement in the swelling and is due to receive 12 months of antibiotic therapy. Despite awareness of atypical mycobacterial infections, diagnosis is frequently delayed, leading to increased morbidity. Patients with exposure to these atypical pathogens require a broadened differential to include appropriate testing and culture of specimens to obtain an accurate diagnosis.

Tuberculosis is the leading cause of lymphadenopathy in HIV-infected persons in India: Results of a fine-needle aspiration analysis

HIV infection is associated with a number of opportunistic infections and malignancies frequently involving the lymph nodes. Lymphadenopathy may occur at any stage of HIV infection. We aimed to determine the utility of fine-needle aspiration cytology in evaluating the causes of lymphadenopathy in HIV-infected individuals. Three hundred HIV-infected individuals with lymphadenopathy were included in the study. Fine-needle aspiration (FNA) was performed on peripheral or deep-seated lymph nodes. The material was used for cytological examination using May-Grunwald-Giemsa and haematoxylin and eosin staining. Special stains such as modified Ziehl-Neelsen staining for acid-fast bacilli and periodic acid-Schiff staining for fungi were also performed. The mean age of the study group was 35.0 ± 8.0 y (range 13-74 y). The median CD4 count was 152 cells/μl. Out of the 300 FNA reports, acid-fast bacteria were reported in 130 and cytological findings indicating mycobacterial infection in a further 43 patients. Cryptococcosis was reported in 4 individuals, histoplasmosis in 2 and aspergillosis in 1. Reactive hyperplasia was seen in 89 individuals. Lymphoma was noted in 7 individuals and suppurative inflammation in 5. In conclusion, tuberculosis is the predominant cause of lymphadenitis in HIV-infected individuals in India, especially in those with low CD4 cell counts.

Diagnosis of Tubercular Lymphadenopathy by Fine Needle Aspiration Cytology, Acid-Fast Staining and Mantoux Test

This study was undertaken to evaluate the role of Ziehl-Neelsen stain (for acid-fas bacilli), and Mantoux test in diagnosing tubercular lymphadenopathy on FNAC. FNAC was performed on patient with superficial lymphadenopathy. Ziehl-Neelsen stain for acid fast bacilli was done in all cases where cheesy or purulent material was aspirated and smear showed granulomatous lymphadenitis. A Mantoux test was also done in these patients. A Mantoux test was further done in patients of reactive lymphadenopathy where the lymph node size was more than 1 cm. If the result was positive, a repeat FNAC was performed. When the repeat FNAC showed ill-defined granulomas, excision biopsy was done. Tubercular lymphadenopathy was seen in 122 (48.2%) cases. Acid- fast bacilli were found in 71 (58.1%) cases. Mantoux test was positive in 112 (91.8%) cases. A repeat FNAC was done in seven of 11 patients where the cytologic features of tuberculosis were not seen but the lymph node size was more than 1 cm and Mantoux test was positive. The repeat FNAC showed ill-defined granulomas without necrosis. Excision biopsy done in these patients diagnosed them as tubercular lymphadenitis in five of the seven cases, the remaining two cases being diagnosed as reactive lymphadenitis. FNAC coupled with Ziehl - Neelsen staining for AFB and Mantoux test improves the diagnostic efficiency for tubercular lymphadenopathy.

Rapid and Specific Diagnosis of Tuberculous Pleuritis With Immunohistochemistry by Detecting Mycobacterium Tuberculosis Complex Specific Antigen MPT64 in Patients From a HIV Endemic Area

The aim of the study was to evaluate the diagnostic potential of immunohistochemistry using an antibody to the secreted mycobacterial antigen MPT64, specific for Mycobacterium tuberculosis complex organisms, on formalin-fixed biopsies from patients with pleural tuberculosis (TB) from a high TB and HIV endemic area. Pleural biopsies from 25 TB cases and 11 non-TB cases were studied. Ziehl-Neelsen staining for acid-fast bacilli and immunohistochemistry with anti-MPT64 and anti-Bacille Calmette-Guérin (BCG) antibodies was performed. Nested polymerase chain reaction (N-PCR) for IS6110 was performed for comparison. Acid-fast bacilli were detected in only 2 cases and 3 biopsies showed granulomas with caseous necrosis. Immunostaining with anti-MPT64, anti-BCG, and N-PCR were positive in 20 (80%), 12 (48%), and 16 (64%) of the cases, and 0, 3 (27%), and 2 (18%) of the non-TB controls, respectively. The diagnostic validity of immunohistochemistry was calculated by comparison with N-PCR-positive TB cases and N-PCR-negative non-TB controls. The sensitivity of immunohistochemistry with anti-MPT64 and anti-BCG were 81% and 56% respectively, and the corresponding specificities were 100% and 78%. Detection of the MPT64 antigen by immunohistochemistry improves the diagnosis of TB pleuritis caused by M. tuberculosis complex organisms in patients living in HIV-endemic areas with atypical histology and negative staining for acid-fast bacilli.

Tuberculose do timo

Tumors of the anterior mediastinum include several entities with different radiological and clinical manifestations, constituting a heterogeneous group of congenital, inflammatory, and neoplastic conditions. Among these lesions, the most common primary tumor of the mediastinum is thymoma, nearly followed by germ cell tumors and lymphomas. Tuberculosis of the thymus, an extremely rare condition, typically involves the mediastinal lymph nodes. We present, in this study, pathological, radiological, and clinical findings of one case of tuberculosis of the thymus in an 18-year-old patient who presented thoracic pain, dyspnea upon minimal effort, and progressive worsening of the symptoms in one week. The chest X-ray showed a large mass in the mediastinum, and computed tomography scans indicated that it was located anteriorly. The patient was submitted to surgery in order to excise the mass. Microscopy revealed a massive inflammatory response and granulomas in the thymic tissue. Ziehl-Neelsen staining for acid-fast bacilli yielded positive results, and a diagnosis of tuberculosis was made. Surgeons and pathologists should remain alert for this condition and should include it in the differential diagnosis of mediastinal masses.

Tuberculous adenitis: comparison of CT and MRI findings with histopathological features

Our aim was to investigate the relationship between the various histopathological features and the CT and MRI findings in routinely submitted histopathological specimens for the diagnosis of tuberculous lymphadenopathy. Twelve formalin-fixed, paraffin-embedded tissue blocks from ten patients who were clinically suspected of having tuberculous lymphadenopathy were evaluated. We assessed the presence of histopathological features including granuloma formation, caseous necrosis, and presence of Langhans-type giant cells, calcifications, fibrosis or normal lymphoid tissue. We performed polymerase chain reaction (PCR)-based assay for mycobacterial DNA and Ziehl-Neelsen staining for acid-fast bacilli (AFB). Findings were compared with those of CT and MRI, including signal intensities on unenhanced MR images, lymph node homogeneity, attenuation values on contrast-enhanced CT and enhancement patterns on MRI. Based on CT and MRI findings, four lymph node types could be defined: (1) homogeneous nodes, visible on both pre- and post-contrast images and corresponding histopathologically to granulation tissue without or with minimal caseation necrosis (n = 2); (2) heterogeneous nodes, showing heterogeneous enhancement patterns with central non-enhancing areas and corresponding to minor or moderate intranodal caseation/liquefaction necrosis (n = 3); (3) nodes showing peripheral rim enhancement and corresponding to moderate or extensive intranodal caseation/liquefaction necrosis (n = 5); (4) heterogeneous nodes showing intranodal hyperdensities on CT and hypointense areas on T1- and T2-weighted images and corresponding to fibrosis and calcifications (n = 2). On CT and MRI, the findings reflect different stages of the tuberculous process. Imaging findings depend on the presence and the degree of granuloma formation, caseation/liquefaction necrosis, fibrosis and calcifications.

Evaluation of the BDProbeTec strand displacement amplification assay in comparison with the AMTD II direct test for rapid diagnosis of tuberculosis

The BDProbeTec MTB assay for direct detection of Mycobacterium tuberculosis was evaluated in comparison with the AMTD-II assay on 94 samples from different patients with clinical suspicion of tuberculosis. Using a combination of culture on Lowenstein-Jensen medium (with or without preculture in BACTEC 9000) and clinical diagnosis as the standard, BDProbeTec MTB showed high sensitivity and specificity (96.1% and 100%, respectively), similar to AMTD-II (96.1% and 97.1%, respectively), with significantly higher sensitivity than the Ziehl-Neelsen stain for acid-fast bacilli (73%, p < 0.05).

Comparison of polymerase chain reaction with histopathologic features for diagnosis of tuberculosis in formalin-fixed, paraffin-embedded histologic specimens.

Objective.-To investigate the relationship between various histopathologic features and the results of the tuberculosis (TB)-polymerase chain reaction (PCR) method in routinely submitted histologic specimens for the histopathologic diagnosis of TB. Design.-We used 95 formalin-fixed, paraffin-embedded tissue blocks from 81 patients who were clinically suspected of having TB. We assessed the presence of histopathologic features including well-formed granuloma, poorly formed granuloma, caseous necrosis, and Langhans-type giant cells. We performed nested PCR for IS6110 and Ziehl-Neelsen staining for acid-fast bacilli (AFB). Results.-Of the 81 patients studied, 53 patients had chronic granulomatous inflammation, whereas 28 patients had only chronic inflammation without definite granulomatous inflammation. Of the 53 cases with chronic granulomatous inflammation, 17 (32%) were AFB positive and 36 (68%) were TB-PCR positive. Among cases with chronic granulomatous inflammation, the percentage that were positive and negative by TB-PCR differed significantly with the presence of various histopathologic features. All of the 13 cases with well-formed granuloma, caseous necrosis, and Langhans-type giant cells were TB-PCR positive; however, 10 (36%) of the 28 cases with chronic inflammation without granulomatous lesions were also TB-PCR positive. Conclusions.-TB-PCR is a rapid, sensitive method for the diagnosis of TB in routinely processed formalin-fixed, paraffin-embedded histologic specimens and is readily available in histopathology laboratories. We recommend use of TB-PCR when TB is suspected clinically, especially in cases of chronic inflammation without definite evidence of granulomatous inflammation.