Diagnosis: Typical Carcinoid

 

Radiologic Findings

Chest radiograph shows well-marginated, round, solitary pulmonary nodule of 2.5 cm in diameter in right upper lobe. Thin-section CT scan with IV contrast (100 cc, 2 cc/sec) shows moderate contrast enhancement (20-25 HU) of the nodule with focal area of central low attenuation. No calcification is seen.
Pathologic examination on the tumor obtained with right upper lobectomy confirmed typical carcinoid.
In this particular case, contrast enhancement was not that remarkable.

 

Brief Review

 
1. Carcinoid tumor is a low-grade malignant tumor, only about 0.5 % to 2.5 % of all pulmonary neoplasm.  Typical carcinoid represents 80 % to 90 % of carcinoid tumors.

2. A part of neuroendocrine carcinoma of the lung (typical carcinoid - atypical carcinoid - small cell carcinoma - large cell neuroendocrine carcinoma, non-small cell carcinoma with neuroendocrine feature)

3. Slightly female preponderance, at the age of late 30s to late 40s.

4. Good prognosis with infrequent lymph node spread and rare distant metastasis.

5. Radiologic findings depend on the location of the tumor.

   1) Central tumor (up to 80 % of carcinoid tumors): atelectasis or postobstructive pneumonitis.
                                                              Endobronchial component is readily seen with CT scan.

   2) Peripheral tumor: solitary pulmonary nodule less than 3 cm in diameter in most cases,
                                       often calcified (approximately 30% of the tumor with CT and pathologic studies).

    CT with IV contrast shows strong enhancement due to vascular nature of the tumor.
 

 

References

1. Foster BB, Muller NL, Miller RR, Nelems B, Evans KG. Neuroendocrine carcinomas of the lung: clinical, radiologic, and pathologic correlation. Radiology 1989; 170:441-445
2. Fraser RS, Muller NL, Colman N, Pare PD. Diagnosis of diseases of the chest. 4th ed. Saunders: Philadelphia, 1999; 1229-1243


An application letter from Dr. Ivan Pilate in Belgium, which contains many important differential diagnoses

Dear Dr. Kim,
  
About case 162 :
Incidental finding : well-defined SPN, no calcification, discrete contrast enhancement.
  

My differential diagnoses :   

1. tumoral : hamartoma and carcinoid.

Bronchial carcinoma, lymphoma amd metastasis are less likely.

Other tumoral diseases are rare : bronchial gland tumors (adenoid cystic ca, mucoepdermoid ca)
and mesenchymal tumors (sarcoma, hemangiopericytoma).

Another group 'tumors' are also very rare : inflamatory pseudotumor, pulmonary hyalizing granuloma.   

2. bronchogenic cyst (eventually with complication : infection, neoplasia) and lung sequestration.   

3. infectious disease : coccidiomycosis and Paragonimiasis, Dirofilariasis.   

4. other : endometriosis.

I don't believe it can be mucoid impaction.
  
  
With best wishes,

Dr. Ivan Pilate
Stedelijk OLV-Ziekenhuis Mechelen
Belgium


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