Clinical identification of malignant pleural effusions

INTRODUCTION

Pleural effusions frequently signal disseminated cancer. Diagnostic markers of pleural malignancy at presentation that would assess cancer risk and would streamline diagnostic decisions remain unidentified.

METHODS

A consecutive cohort of 323 patients with pleural effusion (PE) from different etiologies were recruited between 2013 and 2017 and was retrospectively analyzed. Data included history, chest X-ray, and blood/pleural fluid cell counts and biochemistry. Group comparison, receiver-operator characteristics, unsupervised hierarchical clustering, binary logistic regression, and random forests were used to develop the malignant pleural effusion detection (MAPED) score. MAPED was validated in an independent retrospective UK cohort (n = 238).

RESULTS

Five variables showed significant diagnostic power and were incorporated into the 5-point MAPED score. Age > 55 years, effusion size > 50% of the most affected lung field, pleural neutrophil count 〈 2,500/mm3, effusion protein 〉 3.5 g/dL, and effusion lactate dehydrogenase > 250 U/L, each scoring one point, predicted underlying cancer with the area under curve(AUC) = 0.819 (P < 10-15) in the derivation cohort. The integrated discrimination improvement of MAPED scores showed an increase compared to cytology (p <0.001). Decision curve analysis indicated that the MAPED score generated net clinical benefit. In the validation dataset, the AUC of MAPED scores was 0.723 ( P = 3 × 10-9) for the MAPED score. Interestingly, MAPED correctly identified 33/42(79%) of cytology-negative patients that indeed had cancer.

CONCLUSIONS

The MAPED score identifies malignant pleural effusions with satisfactory accuracy and can be used complementary to cytology to streamline diagnostic procedures.

CONDENSED ABSTRACT

Diagnostic markers for malignant pleural effusions remain uncertain. The MAPED score identifies malignant pleural effusions and complements cytology and confers no additional risk to the patient or cost to the healthcare system.

Combination of commercially available molecular assays and culture based methods in diagnosis of tuberculosis and drug resistant tuberculosis

Early diagnosis of tuberculosis is of major clinical importance. Among 4733 clinical specimens collected from 3363 patients and subjected to Ziehl–Neelsen microscopy, 4109 were inoculated onto Löwenstein–Jensen slants and 3139 in Bactec/9000MB. Polymerase Chain Reaction (PCR) was performed in 3139 specimens, whereas, a genotypic assay was directly applied in 93 Mycobacterium tuberculosis complex PCR-positive for isoniazid and rifampicin resistance detection specimens (GenoType MTBDRplus). Recovered M. tuberculosis isolates (64) as well as, 21 more sent from Regional Hospitals were tested for antimycobacterial resistance with a phenotypic (manual MGIT-SIRE) and a genotypic assay (GenoType MTBDRplus). PCR in the clinical specimens showed excellent specificity (97.4%) and accuracy (96.8%), good sensitivity (70.4%), but low positive predictive value (40.3%). MGIT-SIRE performed to M. tuberculosis did not confer a reliable result in 16 isolates. Of the remaining 69 isolates, 15 were resistant to streptomycin, seven to isoniazid, seven to ethambutol and five to rifampicin. GenoType MTBDRplus correctly detected isoniazid (seven) and rifampicin-resistant M. tuberculosis strains (five), showing an excellent performance overall (100%). Susceptibility results by the molecular assay applied directly to clinical specimens were identical to those obtained from recovered isolates of the corresponding patients. Combining molecular and conventional methods greatly contribute to early diagnosis and accurate susceptibility testing of tuberculosis.

Pleural mesothelioma in a young male patient

We present the case of a 33-year-old male patient suffering from lymphocytic pleural effusion, as a result of pleural mesothelioma. Mesothelioma is a malignant tumor of the pleura that is mainly caused by chronic exposure to asbestos fibers and more than 40 years of exposure are needed to develop the disease. Early studies on the relationship of asbestos and mesothelioma were issued in the 1960s. Fibers migrate from the parenchyma of the lung to the visceral pleura. It is widely known that asbestos is an oncogenic factor which can cause damage to DNA. A chest x-ray may reveal pleural effusion with or without pleural thickening, whereas a chest CT may also reveal pleural thickening, uniform and/or lobular. Specific tests, such as immunohistochemical staining, are used in order to help differential diagnosis. Extrapleural pneumonectomy is used as a therapeutic option which involves removal of the lung as well as both the visceral and parietal pleura, the affected part of the pericardium and diaphragm. Surgery should be followed up by radiotherapy and chemotherapy. The surgery may lead to a mean survival rate of approximately 9-21 months. The case presented underlines that in the event of pleural effusion with a lymphocyte type physicians should consider the possibility of a pleural mesothelioma during differential diagnosis, even in relatively young patients.