Lung cavities in chronic thromboembolic pulmonary hypertension

OBJECTIVES: Chronic thromboembolic pulmonary hypertension (CTEPH) is a unique form of pulmonary hypertension (PH) that arises from obstruction of the pulmonary vessels by recanalized thromboembolic material. CTEPH has a wide range of radiologic presentations. Commonly, it presents as main pulmonary artery enlargement, peripheral vascular obstructions, bronchial artery dilations, and mosaic attenuation patterns. Nevertheless, other uncommon presentations have been described, such as lung cavities. These lesions may be solely related to chronic lung parenchyma ischemia but may also be a consequence of concomitant chronic infectious conditions. The objective of this study was to evaluate the different etiologies that cause lung cavities in CTEPH patients. METHODS: A retrospective data analysis of the medical records of CTEPH patients in a single reference PH center that contained or mentioned lung cavities was conducted between 2013 and 2016. RESULTS: Seven CTEPH patients with lung cavities were identified. The cavities had different sizes, locations, and wall thicknesses. In two patients, the cavities were attributed to pulmonary infarction; in 5 patients, an infectious etiology was identified. CONCLUSION: Despite the possibility of being solely associated with chronic lung parenchyma ischemia, most cases of lung cavities in CTEPH patients were associated with chronic granulomatous diseases, reinforcing the need for active investigation of infectious agents in this setting.

Comparison of Ziehl-Neelsen Stain and TB-PCR on Detection of Mycobacterium tuberculosisin Formalin-fixed, Paraffin-embedded Tissues of Chronic Granulomatous Inflammation

BACKGROUND: TB-PCR is a faster and more sensitive method to detect mycobacterium than acid-fast bacilli (AFB) stain, which is laborious and time consuming. We compared the sensitivity and specificity of AFB stain and TB-PCR and examined the possibility of TB-PCR as a confirmative test without AFB stain in the diagnosis of tuberculosis. METHODS: We performed Ziehl-Neelsen stain and nested PCR using a commercially available TB-PCR kit amplifying IS6110 sequence in 81 cases of paraffin-embedded tissues diagnosed as chronic granulomatous inflammation. In addition, we evaluated the morphology of granuloma and the presence of caseation necrosis. RESULTS: Of the 81 cases studied, 22 (27.2%) and 40 (49.4%) were positive for AFB stain and TB-PCR, respectively. Of 49 cases accompanying caseation necrosis, 19 (38.8%) were AFB stain positive and 37 (75.5%) were TB-PCR positive; a result that is comparable with that of other reports. Of the 22 AFB-positive cases, 2 were TB-PCR negative. CONCLUSION: TB-PCR is very helpful for the diagnosis of tuberculosis in routinely processed, formalin-fixed, paraffin-embedded tissue samples. Nevertheless, AFB stain should continue to be performed at the same time.