Diagnosis: Adenoid Cystic Carcinoma
 

Radiologic Findings

Chest radiograph shows a relatively well-defined and lobulated soft tissue density in the left hilar area with obliteration of left cardiac border.   Both mediastinal and lung window images of CT scan show huge lobulated heterogeneous enhancing mass in the left upper lobe with intraluminal protruding mass in left upper lobar bronchus, and associated with adjacent distal atelectasis. Stippled and curvilinear calcifications are noted within the mass lesion.   On enhanced CT scan obtained at the level of carina, the left pulmonary artery is invaded by protruding mass.

 

Brief Review

Adenoid cystic carcinoma is the second most common primary malignant tumor of the tracheobronchial trees.   About 80% of the tumors arise in the trachea and both main stem bronchi with equal frequency; most of remainders occur in the lobar bronchi.   Unlike squamous cell carcinoma, adenoid cystic carcinoma appears to be unrelated to smoking.   There is no gender predominance and the average age of patients is 40 to 45 years.   Adenoid cystic carcinoma is a non-encapsulated tumor that grows extremely slowly.   Spread tends to occur characteristically in the airway lumen and infiltrate submucosally or perineurally for long distance.   They may infiltrate through the fibrous membrane between adjacent cartilage plates into peritracheal tissue.   Extraluminal growth in the transverse plane is a common feature of adenoid cystic carcinoma.   Like bronchial carcinoid and other various benign tumors, adenoid cystic carcinoma may have internal calcification.   Metastasis to regional lymph nodes may present in 10% of the cases at the time of diagnosis.   Distant metastases may occur in the lung, liver, abdomen, lymph nodes, or bones.

 

References

1. DG Na, MH Han, KH Kim, et al. Primary adenoid cystic adenoma of the cervical trachea mimicking thyroid tumor: CT evaluation. JCAT 1995;19:559-563 2. Spizarny DL, Shepard JO, McLoud, et al. CT of adenoid cystic adenoma of trachea. AJR 1986;1129-1132

A message from Dr. Kyung Soo Lee at Samsung Medical Center

Dear Dr. Kim:
 
Calcified central (bronchial) mass with atelectasis of left upper lobe in a 56-year-old woman is all findings that I can see.
The central mass has extraluminal component of the tumor. Do you think it is specific for this disease? I don't think so.
 
The possible diagnoses include squamous cell carcinoma, large cell neuroendocrine carcinoma of the lung, carcinosarcoma,
and rarely carcinoid tumor. However, the findings are totally nonspecific. You should mention it in discussion.
 
With best wishes.

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