대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Courtesy

S

Imaging Findings

Chest radiograph shows dense and prominent right hilum. (Fig.1)
On CT scan, a sharply defined, 3.5 x 3.5 cm-sized, totally ossified mass is centrally situated in the right lower lobar bronchus,
which produces abrupt bronchial obstruction.
However, peripheral atelectasis or distal mucoid impaction is not seen.
Some portion of bronchus intermedius wall is surrounded by nodular calcification (Figs. 2 & 3).

Discussion

Carcinoids are neuroendocrine neoplasms, which occur most frequently in the gastrointestinal tract.
The second most common location is the respiratory tract.
Bronchial carcinoid is an uncommon pulmonary neoplasm, which represent 1-2% of all lung tumors.

Bronchial carcinoids display a spectrum of clinical behavior and histologic differentiation,
ranging from the low-grade typical carcinoids to the intermediate-grade atypical carcinoids
to the high-grade large-cell neuroendocrine carcinomas and small cell carcinomas.

In general, patients with bronchial carcinoids are younger than those with common primary pulmonary neoplasms
such as bronchogenic carcinoma.
The age of patients with atypical carcinoid is one decade greater (6th decade of life) than that of those with typical carcinoid.

Hemoptysis is frequent and occurs in approximately 50% of patients.
However, up to 19-51% of patients is asymptomatic
and bronchial carcinoid is diagnosed incidentally because of abnormal findings at chest radiography.
The high frequency of symptoms in patients with bronchial carcinoids is probably related to the frequent central location of the tumor.

The carcinoid syndrome is rarely seen in association with bronchial carcinoid.
It is seen in less than 2-5% of patients with bronchial carcinoid, is usually encountered only in patients with
metastatic carcinoid to the liver, and rarely if ever in patients with isolated bronchial tumors.

The most frequent radiographic manifestation of bronchial carcinoid is a hilar or perihilar mass,
which may represent an isolated finding or may be associated with distal parenchymal disease.
The mass is characterically well-circumscribed, is rounded or ovoid, and may have a notched or lobulated contour.
Masses with irregular or ill-defined margins are rarely seen.

Atypical carcinoids are reported to be larger on average than typical carcinoids.
Calcification is rarely visible radiographically.
Islands of calcification or ossification were first described in carcinoid tumors in 1938;
up to 30% of cases show some histologic ossification,
but of a degree insufficient to allow visualization on routine chest radiography.
It was believed that this represented the reaction of engulfed bronchial cartilage especially in the more common central carcinoids.

Metastases are rare and late;
the relative resectability and curability of these tumors far exceeds that of other primary pulmonary malignancies.
The ten-year survival rate is 88% for the typical carcinoid.

Reference

1. Donna M, Stanley SS, Joseph CE, et al. Pulmonary carcinoid tumors: CT assessment. J Comput Assist Tomogr 1989; 13:244 -247
2. Melissa LR, Gerald FA, Wanda MK, et al. Thoracic carcinoids: radiologic-pathologic correlation. RadioGraphics 1999; 19:707-736
3. Rosalind HT. Ossifying bronchial carcinoid: A case report. AJR 1968; 104:808-809

Keywords

Airway, Malignant tumor,