Polymerase chain reaction for detection of Mycobacterium tuberculosis in papanicolaou-stained fine needle aspirated smears for diagnosis of cervical tuberculous lymphadenitis.

A polymerase chain reaction (PCR) protocol for detecting IS6110 repetitive insertion sequence of Mycobacterium tuberculosis (MTB) was tested on archival Papanicolaou (Pap)-stained fine needle aspirated (FNA) smears from 24 patients with cervical tuberculous lymphadenopathy and 30 negative controls. The protocol involved protease digestion or phenolchloroform extraction, and simple or nested PCR, with PCR amplification of human beta-globin gene for internal control of DNA quality. Sensitivity of 50% and specificity of 100% were obtained. Sensitivity in smears showing necrosis without granuloma was 70% (7/10), whereas it was 36% (5/14) in smears with presence of granuloma. On the other hand, sensitivity of 18% (4/22) was obtained using FNA acid-fast stain, 25% (1/4) for acid-fast stain in histological section, 50% (2/4) for culture, and 100% (8/8) for PCR of fresh specimens. PCR for MTB detection in Papanicolaou-stained slides is a practical and valuable method when no fresh specimen but only Pap-stained smear is available.

Histopathologic characteristics of pulmonary adenocarcinomas with and without EGFR mutation.

EGFR mutation played crucial role for responsiveness of non-small cell lung cancers to EGFR tyrosine kinase inhibitors. Almost the mutations were present in adenocarcinomas. Few had studied on histopathologic correlation with EGFR mutation in pulmonary adenocarcinomas. To obtain better view on pathobiology of pulmonary adenocarcinomas, we correlated exons 19 and 21 mutations with various histopathologic features by dissecting particular histological patterns from 60 surgically resected adenocarcinomas. RESULTS: Gland-forming pattern, including bronchiloloalveolar carcinoma (BAC), well-formed acinar, and poorly-formed acinar patterns more frequently contains EGFR mutations than solid pattern (72.7% vs. 23.1%, p = 0.002). EGFR mutations of each within the gland-forming pattern are not significantly different. Micropapillary pattern revealed less exon 19 mutations than the gland-forming pattern (12.5% vs. 66.7%, p = 0.018), but tended to have more Exon 21 mutations than the others (33.3% vs. 11.9%, p = 0.10). Tumors predominated by BAC pattern more commonly had exon 19 mutations than non-BAC predominated tumors (68.8% vs. 39.5%, p = 0.046). EGFR-mutated tumors comprised less proportion of papillary pattern than tumors without mutation (mean = 1.5% vs. 11.2%, p = 0.049). Terminal respiratory unit (TRU) histology was associated with more EGFR mutations (72.4% vs. 42.1%, p = 0.036). Tumors smaller than 3.5 cm had more EGFR mutations than larger tumors (73.1% vs. 41.9%, p = 0.018). CONCLUSION: High frequency of the mutation does not present only in BAC pattern, but also in well-formed and poorly-formed acinar patterns, suggesting them as usual spectrum of EGFR mutated adenocarcinomas. Other characteristics of EGFR-mutated adenocarcinomas include TRU-type histology, smaller size, and less solid phenotype.

Bronchiolitis obliterans organizing pneumonia caused by capsule-deficient cryptococcosis.

A 67-year-old diabetic man presented with progressive multifocal myeloradiculopathy for 6 months, with no pulmonary symptoms. A chest x-ray and CT scan of the lungs revealed bilateral multiple nodular infiltrates in the right upper lobe and the lower lobes bilaterally, mimicking metastases. A thoracoscopic lung biopsy demonstrated bronchiolitis obliterans organizing pneumonia caused by capsule-deficient cryptococcosis.

Metastatic potentiality of micropapillary and conventional histological patterns: a comparative study of 82 pulmonary adenocarcinomas.

BACKGROUND: The recently described micropapillary pattern (MPP) is potentially a strong unfavorable prognostic marker for adenocarcinoma of the lung. None of the previous studies compared the association to nodal metastasis between conventional histological patterns and MPP. METHOD: Histological patterns (1=solid, 2=poorly formed acinar 3=well formed acinar, 4=papillary, 5=bronchioloalveolar), and MPP were semiquantitatively evaluated in 82 pulmonary adenocarcinomas and correlated with nodal status. RESULTS: Mean percentages of pattern 1 and 2 are higher in node positive (N+) group (33.9% vs 19.3%, p=0.046; and 20.8% vs 13.4%, p=0.19, respectively). Analysis of the combined amount of pattern 1 and 2 revealed increased statistical significance (54.6% vs 32.5%, p=0.007). Mean percentages of pattern 3, 4 and 5 tended to be lower in N+ group (22.8% vs 29.4%, p=0.24; 2.8% vs 6.2%, p=0.33; and 17.9% vs 31.2%, p=0.053, respectively). Analysis of the combined amount of pattern 3, 4 and 5 showed increased statistical significance (43.3% vs 66.8%, p=0.005). Mean percentage of MPP was higher in N+ group (28.3% vs 11.3%, p=0.0007) after excluding the cases with more than 80% percent of pattern 1 and 2. The criterion of MPP > or = 20% or combined pattern 1 and 2 > 50% of tumor is strongly associated with nodal metastasis (p=0.0015). Pattern 1 has the highest rate of correspondence of having a similar pattern in metastases (18/26, 69.2%), followed by MPP (10/19, 52.6%), and pattern 2 (12/23, 52.2%). CONCLUSION: MPP has comparable metastatic impact to the solid and the poorly formed acinar patterns and it is prognostically informative to document the presence or absence of the solid plus poorly formed glandular pattern > 50% and MPP > or = 20% when histological subtype is evaluated.

A comparative study of diagnostic tests for tuberculous lymphadenitis: polymerase chain reaction vs histopathology and clinical diagnosis.

To compare diagnostic tests for tuberculous lymphadenitis by polymerase chain reaction (PCR) with histopathology and clinical diagnosis in sensitivity, specificity and predictive value. This retrospective analytic, single blind study was done at King Chulalongkorn Memorial Hospital. Paraffin-embedded specimens were classified into 2 groups. The study group contained 30 proved AFB positive paraffin-embedded specimens from patients who also had clinical diagnosis of tuberculosis and improved by antituberculous treatment. The control group contained 30 formalin-fixed, paraffin-embedded specimens of lymph node hyperplasia proved by histopathological and clinical review. All 60 specimens were slided, and systematically labeled and sent to PCR lab. Polymerase Chain Reaction method had sensitivity = 43.33 per cent, specificity = 100 per cent, positive predictive value = 100 per cent and negative predictive value = 63.83 per cent. The present findings revealed that the PCR results were related to the age of the paraffin-embedded tissues. No positive results were obtained from tissues kept since 1996. Positive results were obtained in 3/7 cases (42.86%), 2/3 (66.67%) and 8/10 cases (80%) from tissue of 1997, 1998 and 1999 respectively. Conclusion: Polymerase chain reaction has sufficient reliability best as a confirmatory diagnostic test for tuberculous lymphadenitis; however, it is not appropriate as a screening test.