Congenital pulmonary airway malformation

Congenital Pulmonary Airway Malformation (CPAM), formerly known as Congenital Cystic Adenomatoid Malformation (CCAM), is a developmental anomaly of the lung characterized by cystic or adenomatoid malformation. It is a type of congenital lung disease that affects the bronchial structures and is present at birth. CPAM is a rare condition that can vary greatly in its presentation and severity, ranging from a single cyst to multiple cysts affecting an entire lung lobe.

Classification

CPAM is classified into five types based on the size and appearance of the cysts as well as the affected lung tissue. These types are:

• Type 0: Proximal acinar dysplasia, the most severe form, often incompatible with life.
• Type 1: The most common type, characterized by large cysts up to 10 cm in diameter.
• Type 2: Features smaller cysts, less than 2 cm, and is often associated with other congenital anomalies.
• Type 3: Microcystic malformation with very small cysts, affecting an entire lobe of the lung.
• Type 4: Peripheral acinar dysplasia, with large, peripheral cysts that may resemble emphysema.

Etiology

The exact cause of CPAM is unknown, but it is thought to result from abnormal development of the lung buds during fetal growth. Genetic factors may play a role, although specific genetic mutations have not been consistently identified.

Symptoms

Symptoms of CPAM can vary widely. Some infants may show signs of respiratory distress at birth, including rapid breathing, grunting, or cyanosis. In other cases, CPAM may be asymptomatic and discovered incidentally during prenatal ultrasound or after birth during investigations for unrelated issues.

Diagnosis

CPAM is often diagnosed prenatally through ultrasound. The presence of cystic lesions in the fetal lung can suggest the diagnosis, which can be further evaluated with fetal MRI for a more detailed assessment. After birth, chest X-rays, CT scans, and MRI can be used to confirm the diagnosis and assess the extent of the disease.

Treatment

The treatment of CPAM depends on the severity of the condition. Asymptomatic cases may be monitored for signs of infection or respiratory distress. In symptomatic infants, surgical removal of the affected lung tissue (lobectomy) is often recommended to prevent complications such as infection or pneumothorax. Advances in minimally invasive surgery have improved outcomes for many patients.

Prognosis

The prognosis for infants with CPAM varies depending on the type and severity of the malformation. With appropriate treatment, many children can expect to lead normal lives, although they may be at increased risk for respiratory infections.

Epidemiology

CPAM is a rare condition, with an estimated incidence of 1 in 25,000 to 35,000 live births. There is no known gender or racial predilection.

See Also

• Pulmonary sequestration
• Bronchopulmonary dysplasia
• Congenital diaphragmatic hernia