Carcinoma of the lung causes on astonishing variety of symptoms. Those which
bring about the initial presentation as well as those which develop as the disease
progresses are not only remarkably diverse, but vary widely between patients. It is not
uncommon for the diagnosis to be made during workup of such conditions as Cushing's
syndrome (due to ectopic ACTH production), or of neurological complaints found ultimately
to be due to brain metastases! Therefore, in order to study the clinical manifestations of
this disease in some productive way, it is helpful to group the symptoms lung cancer may
cause into five general categories.
Endobronchial location of the tumor explains many of the symptoms related to primary tumor. If the primary is peripheral and the lesion is in the lung, often the symptoms related to primary tumor are absent.
Several organs or organ systems clearly emerge as the most common sites of distant metastasis for lung carcinoma. These have great bearing on the clinical manifestations of the disease, and are frequently the cause of the clinical manifestations of the disease, and are frequently the cause of the patient's initial presentation!
These are an ever-expanding set of intriguing clinical syndromes involving non-metastatic systemic effects which have been noticed to accompany malignant disease on occasion. Some are associated with a specific cell type; others have no such predilection. Most are felt to be biochemically mediated. Some are just plain mysteries.
When carcinoma of the lung causes symptoms though intrathoracic spread, it tends to do so in only two primary ways:
Whatever the mode of spread, most of the associated symptoms occur once the disease has reached either the chest wall or the mediastinum. If it was central, mediastinal problems tend to occur. If the tumor was located very inferior, diaphragmatic symptoms may be expected. If it began out in the periphery, chest wall problems are usually noted first.
Clinical problems that result from extension to the chest wall aren't difficult to understand. Since the parietal pleura is one of the few pain-sensitive structures in the area, this may be the first time the patient experiences pain. Pleural effusion is also a common condition related to this process. If the tumor happened to start near the apex of the lung, a syndrome knows as "Pancoast Tumor" may develop, involving complaints related to damage of CB-T1 roots.
The following are non-specific symptoms due to tumor burden: