Answer for BIR CoW 18 Feb 2024
Bronchogenic carcinoid
Findings
Case findings - X ray – Triangular opacity noted in the medial aspect of right lower zone causing obscuration of the medial aspect of right hemidiaphragm with tenting of right hemidiaphragm. On lateral radiograph, triangular opacity noted in the retrocardiac region. Features suggestive of right lower lobe collapse. CECT - Evidence of ill- defined homogeneously enhancing soft tissue density lesion with eccentric calcification is noted arising from the endobronchial region of right lower lobe bronchus and growing beyond the bronchial wall into the adjacent lung parenchyma. The mass is causing abrupt cut off of right lower lobe bronchus resulting in complete collapse of right lower lobe. Mucus bronchogram noted in the collapsed right lower lobe. No evidence of any enlarged mediastinal lymph nodes. Right upper and middle lobes are normal. MIP and fly through images – show complete obstruction of right lower lobe bronchus while right middle lobe bronchus appears normal. Diagnosis- Patient is a Known case of HPE proven endobronchial carcinoid, came for follow-up scan. Present study shows, right lower lobe endobronchial carcinoid with extraluminal extension into adjacent parenchyma and complete collapse of right lower lobe.
Discussion
Carcinoid tumors originate from neuroendocrine cells (kulichitsky cells) in the bronchial wall. Carcinoid belong to the group of neuroendocrine tumors which also includes small cell lung cancer, large cell neuroendocrine carcinoma, and DIPNECH. These tumors contain secretory granules, and can produce active peptides. Carcinoids are classified as typical or atypical.
TYPICAL CARCINOID
Age: 40 - 60 years ; slightly more common in women Site: Central (80%) or peripheral (20%) Location: Central bronchi – in the main, lobar or segmental bronchi; 1% intratracheal; Symptoms: - Bronchial obstruction - cough, fever, and wheezing, - Hemoptysis because of high vascularity, - Peripheral carcinoid tumors - asymptomatic. Patterns of growth : - Endoluminal mass ; - Slowly growing - Locally invasive beyond bronchial wall – such tumors may display a dominant extraluminal component with a very small endoluminal portion (iceberg lesion). Metastases : - Regional LN metastases – 15 - 20 % X ray Bronchial obstruction - primarily atelectasis or consolidation, typically limited to a lobe or segment Sometimes air trapping; CT Central tumors - as discrete mass lesions in or near the hila; eccentric calcification in nearly 40% cases; - Large endobronchial component with a convex margin pointing toward the hilum. - can expand he bronchus as they grow, typically resulting in a flaring of the bronchial lumen - Because they are highly vascular, dense enhancement may be seen on CT Peripheral tumors – well defined, round or oval, discrete nodule Radionuclide imaging With somatostatin analogs (e.g., octreotide) may be used to localize an occult carcinoid tumor in a patient with Cushing’s syndrome or carcinoid syndrome or to diagnose metastases.
ATYPICAL CARCINOID
10% to 25% of carcinoid tumors; intermediate grade; Associated with smoking. An endobronchial mass resulting in obstruction is less common, occurring only 10%. Tend to present as a lung nodule or mass, round or ovoid, lobulated, and somewhat larger than those seen with typical carcinoid tumor (10 cm or smaller). Histologic features suggesting a more aggressive behavior, including an increased frequency of mitoses, presence of necrosis Lymph node metastases common approximately 50% ; Have a worse prognosis
Clinical Syndromes Associated with Carcinoid Tumor
1) Carcinoid syndrome – 2% to 5% of patients with pulmonary carcinoid Most common in the presence of liver metastases Flushing, fever, nausea, diarrhea, hypotension, and wheezing; 5 – hydroxytryptamine, bradykinin and prostaglandins Cardiac valvular lesions and heart murmurs associated with this syndrome may be limited to the left side of the heart
2) Cushing’s syndrome – 1% of patients with pulmonary carcinoid ACTH or ACTH-releasing hormone by the tumor
3) MEN 1 syndrome References - Thoracic imaging, Richard Webb, 3rd edition
Findings
Case findings - X ray – Triangular opacity noted in the medial aspect of right lower zone causing obscuration of the medial aspect of right hemidiaphragm with tenting of right hemidiaphragm. On lateral radiograph, triangular opacity noted in the retrocardiac region. Features suggestive of right lower lobe collapse. CECT - Evidence of ill- defined homogeneously enhancing soft tissue density lesion with eccentric calcification is noted arising from the endobronchial region of right lower lobe bronchus and growing beyond the bronchial wall into the adjacent lung parenchyma. The mass is causing abrupt cut off of right lower lobe bronchus resulting in complete collapse of right lower lobe. Mucus bronchogram noted in the collapsed right lower lobe. No evidence of any enlarged mediastinal lymph nodes. Right upper and middle lobes are normal. MIP and fly through images – show complete obstruction of right lower lobe bronchus while right middle lobe bronchus appears normal. Diagnosis- Patient is a Known case of HPE proven endobronchial carcinoid, came for follow-up scan. Present study shows, right lower lobe endobronchial carcinoid with extraluminal extension into adjacent parenchyma and complete collapse of right lower lobe.
Discussion
Carcinoid tumors originate from neuroendocrine cells (kulichitsky cells) in the bronchial wall. Carcinoid belong to the group of neuroendocrine tumors which also includes small cell lung cancer, large cell neuroendocrine carcinoma, and DIPNECH. These tumors contain secretory granules, and can produce active peptides. Carcinoids are classified as typical or atypical.
TYPICAL CARCINOID
Age: 40 - 60 years ; slightly more common in women Site: Central (80%) or peripheral (20%) Location: Central bronchi – in the main, lobar or segmental bronchi; 1% intratracheal; Symptoms: - Bronchial obstruction - cough, fever, and wheezing, - Hemoptysis because of high vascularity, - Peripheral carcinoid tumors - asymptomatic. Patterns of growth : - Endoluminal mass ; - Slowly growing - Locally invasive beyond bronchial wall – such tumors may display a dominant extraluminal component with a very small endoluminal portion (iceberg lesion). Metastases : - Regional LN metastases – 15 - 20 % X ray Bronchial obstruction - primarily atelectasis or consolidation, typically limited to a lobe or segment Sometimes air trapping; CT Central tumors - as discrete mass lesions in or near the hila; eccentric calcification in nearly 40% cases; - Large endobronchial component with a convex margin pointing toward the hilum. - can expand he bronchus as they grow, typically resulting in a flaring of the bronchial lumen - Because they are highly vascular, dense enhancement may be seen on CT Peripheral tumors – well defined, round or oval, discrete nodule Radionuclide imaging With somatostatin analogs (e.g., octreotide) may be used to localize an occult carcinoid tumor in a patient with Cushing’s syndrome or carcinoid syndrome or to diagnose metastases.
ATYPICAL CARCINOID
10% to 25% of carcinoid tumors; intermediate grade; Associated with smoking. An endobronchial mass resulting in obstruction is less common, occurring only 10%. Tend to present as a lung nodule or mass, round or ovoid, lobulated, and somewhat larger than those seen with typical carcinoid tumor (10 cm or smaller). Histologic features suggesting a more aggressive behavior, including an increased frequency of mitoses, presence of necrosis Lymph node metastases common approximately 50% ; Have a worse prognosis
Clinical Syndromes Associated with Carcinoid Tumor
1) Carcinoid syndrome – 2% to 5% of patients with pulmonary carcinoid Most common in the presence of liver metastases Flushing, fever, nausea, diarrhea, hypotension, and wheezing; 5 – hydroxytryptamine, bradykinin and prostaglandins Cardiac valvular lesions and heart murmurs associated with this syndrome may be limited to the left side of the heart
2) Cushing’s syndrome – 1% of patients with pulmonary carcinoid ACTH or ACTH-releasing hormone by the tumor
3) MEN 1 syndrome References - Thoracic imaging, Richard Webb, 3rd edition
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!