Synchronous primary lung carcinoma (SPLC) is a term given to the occurrence of two or more primary lung carcinomas within different portions of the lung in the same time period.
They are thought to carry the same pathophysiological mechanism as metachronous lung carcinoma (i.e. two or more primary lung cancers occurring in different portions of the lung spaced in time). Both synchronous and metachronous lung cancers are sometimes cumulatively described under the umbrella term "multiple primary lung cancer (MPLC)" 1.
On this page:
Epidemiology
They are rare with the reported incidence of synchronous multiple primary lung cancer being reported ranging from 0.26 to 1.33% 5,6.
Pathology
Histology
Synchronous lung carcinomas can be represented by various histological types although statistically they are more commonly represented by squamous cell carcinoma of the lung 5.
Treatment and prognosis
Prognosis can widely vary depending on the stage, grade and subtype of each tumor. In resectable cases, pneumonectomy is the generally considered operation of choice for synchronous unilateral tumors. When bilateral, sequential resection starting with the most advanced lesion has sometimes been proposed 2. As a crude general rule, synchronous cancers are thought to carry a more favorable prognosis compared with metastatic nodules 7.
Differential diagnosis
In imaging consider:
- intrapulmonary metastases from primary lung cancer, i.e. one of the lesions can be a primary while the other metastases
- two or more intrapulmonary from cancer from outside the lung, i.e. both or all lesions are metastases