Typical pulmonary carcinoid tumour

Typical Pulmonary Carcinoid Tumour is a type of neuroendocrine tumor that originates in the lung. It is considered a less aggressive form of lung cancer, characterized by its slow growth and low potential to spread (metastasize) to other parts of the body compared to other lung cancers. Pulmonary carcinoid tumors are classified into two types: typical and atypical, with the former being more common and having a better prognosis.

Etiology

The exact cause of typical pulmonary carcinoid tumors is not well understood. However, several risk factors have been identified, including a family history of carcinoid tumors, smoking, and exposure to certain chemicals. Unlike other forms of lung cancer, smoking is not a significant risk factor for pulmonary carcinoid tumors.

Pathophysiology

Typical pulmonary carcinoid tumors arise from neuroendocrine cells in the bronchial epithelium. These cells are part of the diffuse neuroendocrine system and have the ability to produce hormones. The tumors are generally well-differentiated, meaning they resemble normal cells and tend to grow and spread more slowly than other types of lung cancer.

Clinical Presentation

Patients with typical pulmonary carcinoid tumors may be asymptomatic or present with symptoms related to the obstruction of airways, such as coughing, wheezing, and recurrent pneumonia. In some cases, the tumor can produce hormones leading to Carcinoid Syndrome, characterized by flushing, diarrhea, and wheezing, although this is more common in gastrointestinal carcinoid tumors.

Diagnosis

Diagnosis of typical pulmonary carcinoid tumors involves a combination of imaging studies, such as CT scans and PET scans, and histological examination of tissue samples obtained through bronchoscopy or surgery. Biopsy and histopathological analysis are crucial for distinguishing typical from atypical carcinoid tumors.

Treatment

The primary treatment for typical pulmonary carcinoid tumors is surgical resection, which can be curative in many cases. The extent of surgery depends on the size and location of the tumor. In cases where surgery is not feasible, other treatments such as radiotherapy or chemotherapy may be considered. However, these tumors are generally less responsive to chemotherapy and radiotherapy compared to other types of lung cancer.

Prognosis

The prognosis for patients with typical pulmonary carcinoid tumors is generally favorable, with a high 5-year survival rate, especially when the tumor is detected early and completely resected. The recurrence rate is low, but long-term follow-up is recommended to monitor for recurrence or the development of additional tumors.

Epidemiology

Typical pulmonary carcinoid tumors are rare, accounting for less than 5% of all lung tumors. They can occur at any age but are most commonly diagnosed in individuals between the ages of 40 and 60. There is no significant gender predilection.