Small cell carcinoma as the cause for a nondiagnostic V/Q lung scan.

Pulmonary thromboembolism (PTE) is a common cause of morbidity and mortality in an emergency department patient population. The advent of ventilation/perfusion (V/Q) lung scanning and the more recent publication of well- controlled analysis of results, such as the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) data, have provided the clinician with effective diagnostic algorithms to use in suggestive cases. However, there are disorders other than PTE, such as bronchogenic carcinoma, that can cause characteristic abnormalities in V/Q scanning. One such case is described in this report.