Pulmonary hamartoma

Case contributed by Dr Mikkaela McCormack


A 30-year-old woman came through the Emergency Department with symptoms of pneumonia. A chest x-ray revealed an incidental 2 cm nodule within the right lung. An excisional biopsy was performed.

Patient Data

Age: 30 years
Gender: Female

The section shows alveolated lung parenchyma with a solitary, well-circumscribed, nodule showing a lobulated architecture and composed of cytologically bland mature chondroid and adipose tissue.  There is no evidence of atypia or malignancy and the lesion was clear of the pathological margin. 

20x H&E: The lesion is solid and sharply delineated from the surrounding parenchyma.  At low power, the admixture of chondroid and adipose tissue can be appreciated. 

40x H&E: At higher power, it can be seen that both chondroid and adipose components are formed by mature cells displaying no worrying cytological or architectural features.  

Case Discussion

This was a classic incidental presentation of a benign, hamartomatous lesion, with a characteristic lobulated architecture and composed of a haphazard admixture of chondroid and adipose elements showing no features of atypia or malignancy. 

Pulmonary hamartoma should be distinguished from pulmonary chondroma, which is associated with Carney triad and is composed only of cartilage and bone with a peripheral fibrous pseudocapsule and lack adipose, smooth muscle and entrapped pulmonary elements, which may be seen in pulmonary hamartomas. 

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Case information

rID: 43935
Published: 30th Mar 2016
Last edited: 3rd May 2021
System: Chest
Inclusion in quiz mode: Included