Dyspnea in a patient with cancer

The general approach to the patient with a malignancy who presents with dyspnea is similar to that in a patient without a malignancy, but some considerations are more prominent in this situation. Some issues to think about:

Infections:
-post-obstructive pneumonia
-opportunistics: PCP, especially if on prednisone 20mg for over 2 months (or equivalent).
-nosocomial pneumonia
-fungal esp. if neutropenia.
-TB reactivation
-tachypnea as compensation for lactic acidosis in sepsis

Vascular/lymphatic:
-pulmonary embolism
-lymphangitic carcinomatosis
-tumor emboli syndrome (seen in lung, prostate, breast- micromets plugging pulmonary capillaries. PFTs may show diffusion abn).
-secondary pulmonary HTN

Airway:
-endobronchial lesion
-COPD- esp smoker with lung ca,

Neuromuscular:
-Lambert-Eaton
-phrenic nerve involvement
-steroid myopathy

Parenchymal/interstitial (in addition to infectious items above):
-drug effect
-radiation effect

Pleural:
-pleural effusion
-pneumothorax
-pleural involvement of malignancy itself

Cardiac:
-pumonary edema seconary to cardiomyopathy- chemotherapy toxicity (esp. anthracyclines) -pericardial effusion

Other:
-anemia