Characteristics of patients with pseudochylothorax-a systematic review.
BACKGROUND
Pseudochylothorax (PCT) (cholesterol pleurisy or chyliform effusion) is a cholesterol-rich pleural effusion (PE) that is commonly associated with chronic inflammatory disorders. Nevertheless, the characteristics of patients with PCT are poorly defined.


METHODS
A systematic review was performed across two electronic databases searching for studies reporting clinical findings, PE characteristics, and the most effective treatment of PCT. Case descriptions and retrospective studies were included.


RESULTS
The review consisted of 62 studies with a total of 104 patients. Median age was 58 years, the male/female ratio was 2.6/1, and in the 88.5% of cases the etiology was tuberculosis (TB) or rheumatoid arthritis (RA). PE was usually unilateral (88%) and occupied greater than one-third of the hemithorax (96.3%). There was no evidence of pleural thickening in 20.6% of patients, and 14 patients had a previous PE. The pleural fluid (PF) was an exudate, usually milky (94%) and with a predominance of lymphocytes (61.1%). The most sensitive tests to establish the diagnosis were the cholesterol/triglycerides ratio (CHOL/TG ratio) >1, and the presence of cholesterol crystals (97.4% and 89.7%, respectively). PF culture for TB was positive in the 34.1% of patients. Favorable outcomes with medical treatment, therapeutic thoracentesis, decortication/pleurectomy, pleurodesis, thoracic drainage and thoracoscopic drainage were achieved in 78.9%, 47.8%, 86.7%, 66.6%, 37.5% and 42.9%, respectively.


CONCLUSIONS
PCT is usually tuberculous or rheumatoid, unilateral and the PF is a milky exudate. The presence of cholesterol crystals and a CHOL/TG ratio >1 are the most sensitive test for the diagnosis. The lack of pleural thickening does not rule out PCT. Treatment should be sequential, treating the underlying causes, and assessing the need for interventional techniques.
Servicio de Neumología, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain ;
Adriana
A
Lama
Servicio de Neumología, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain;; Grupo Interdisciplinar de Investigación en Neumología, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain;
Lucía
L
Ferreiro
Servicio de Neumología, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain ;
María E
ME
Toubes
Servicio de Neumología, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain;; Grupo Interdisciplinar de Investigación en Neumología, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain;
Antonio
A
Golpe
Unidad de Epidemiología Clínica, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain;; Grupo Epidemiología de Enfermedades Frecuentes, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain;
Francisco
F
Gude
Servicio de Neumología, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain;; Grupo Interdisciplinar de Investigación en Neumología, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain;
José M
JM
Álvarez-Dobaño
Servicio de Neumología, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain;; Grupo Interdisciplinar de Investigación en Neumología, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain;
Francisco J
FJ
González-Barcala
Grupo Interdisciplinar de Investigación en Neumología, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain;; Servicio de Análisis Clínicos, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain.
Esther
E
San José
Servicio de Neumología, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain ;
Nuria
N
Rodríguez-Núñez
Servicio de Neumología, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain ;
Carlos
C
Rábade
Servicio de Neumología, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain ;
Carlota
C
Rodríguez-García
Servicio de Neumología, Complejo Hospitalario Clínico-Universitario de Santiago, Santiago de Compostela, Spain;; Grupo Interdisciplinar de Investigación en Neumología, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain;
Luis
L
Valdés
Pleural effusion (PE); cholesterol PE; chyliform pleural effusion; pleural fluid (PF); pseudochylothorax (PCT)