Malignant Transient Pleural Transudate: A Sign of Early Lymphatic Tumoral Obstruction

Abstract

In the absence of a responsible comorbid condition, the transudative character of a pleural effusion in patients with malignancy does not imply a favorable outcome. We report a case of colon carcinoma metastatic to lung and pleura presenting as a bilateral transudative pleural effusion. Tumoral diffuse lymphatic permeation was identified as the cause of lymphatic obstruction on pleural and transbronchial biopsies. The transudative character of the pleural effusion was transient denoting its obstructive origin.

Thoracoscopy: general overview and place in the diagnosis and management of pleural effusion

“…A malignancy is rarely found in effusions that are borderline between transudates and exudates, especially when there is a preexisting condition provoking transudative effusions [32]. In addition, malignant effusions can sometimes present transiently as transudates in some cases of carcinomatous lymphangitis [33]; this occurs mostly in pleural involvement by nonHodgkin's lymphoma, and when central airway obstruction is present. 2) When there is an exudative effusion present, a total body contrast computed tomography (CT) scan would be highly recommended; it can be of great help in detecting neoplastic pleural deposits [34].…”

Is it Meaningful to use Biochemical Parameters to Discriminate Between Transudative and Exudative Pleural Effusions?

“…but in these cases the classification remains useful. The occurrence of a transudative effusion in a patient with lung cancer in the absence of other potential causes of pleural effusion indicates the presence of pulmonary atelectasis or early lymphatic obstruction, 4,5 findings that may lead the following steps in the diagnostic workup.…”

Lymphangitic Carcinomatosis as a Cause of Malignant Transient Pleural Transudate

“…In fact, as far as we know, the only one case supporting the possibility that a malignancy alone may lead to a transient transudative effusion was published recently by our group [2]. A new similar case, although with some differences that could help to understand some still obscure physiopathological aspects, comes to reaffirm the possible occurrence of this type of transudative effusion.…”

“…Otherwise, it may be that extrapleural lymphatic infiltration allowed the development of a transudative effusion before the tumour invaded the pleural space itself [3]. This last possibility seems the most probable in the published first case [2], in whom within one month, a transudative effusion, with a negative pleural fluid cytology, changed to an exudate, with positive cytology. However, the present case comes to demonstrate that the malignant lymphatic infiltration can produce a pleural effusion with a positive cytology, by an obstructive mechanism, without invading the pleural space itself.…”