Alveolar adenoma

Definition

A solitary peripheral lung tumour consisting of a network of spaces lined by simple low cuboidal epithelium and associated with a scant spindle cell stroma which is sometimes myxoid.

Epidemiology

This is a very rare tumour of adults, slightly more common in women0,6.

Clinical features

This is usually an incidental finding in an asymptomatic patient2.

Radiology

The lesion is solitary and well-circumscribed1,3. It lacks calcification. Magnetic resonance imaging demonstrated the presence of a cystic space with central fluid and thin-rim enhancement3.

Macroscopic appearances

The lesion is lobulated and multicystic.

Histopathology

The cystic spaces are filled with eosinophilic granular material and lined by flattened cuboidal or hobnail Type II pneumocytes2. The cells may have clear cytoplasm7. There may be squamous metaplasia. The stromal spindle cells are bland. A case has been reported with areas resembling sclerosing haemangioma7.

Immunohistochemistry

Ultrastructure

The lining cells contain lamellar bodies and bear blunt microvilli and zona adherens type cell junctions. They appear to be chiefly type II neumocytes4.

Differential diagnosis

• Lymphangioma: lining cells are negative for cytokeratins

• Sclerosing haemangioma: clear/foamy cells are not a dominent feature7. Stromal cells (as well as the epithelial cells) are positive for TTF-17.

•  

• Adenocarcinoma,

  • bronchoalveolar carcinoma: shows lepidic growth

If clear cells are present:

• clear cell tumour of lung
  

• metatstatic renal cell carcinoma

Management

Excision

Prognosis

Benign

References

0 Tumours of the Lung, Pleura, Thymus and Heart. WHO Classification of Tumours. IARC Press 2004.

1 Bohm J, Fellbaum C, Bautz W, et al. Pulmonary nodule caused by an alveolar adenoma of the lung. Virchows Arch 1997; 430:181-4

2 Burke LM, Rush WI, Khoor A, et al. Alveolar adenoma: a histochemical, immunohistochemical, and ultrastructural analysis of 17 cases. Hum Pathol 1999; 30:158-67

3 Fujimoto K, Muller NL, Sadohara J, et al. Alveolar adenoma of the lung: computed tomography and magnetic resonance imaging findings. J Thorac Imaging 2002; 17:163-6

4 Haskovcova I, Povysil C,Pafko P [Alveolar adenoma of the lung (case report)]. Cesk Patol 1997; 33:49-52

5 Koppl H, Freudenberg N, Berwanger I, et al. [Alveolar adenoma of the lung. Immunohistochemical characterization of type II pneumocytes]. Pathologe 1996; 17:150-3

6 Menet E, Etchandy-Laclau K, Corbi P, et al. [Alveolar adenoma: a rare peripheral pulmonary tumor]. Ann Pathol 1999; 19:325-8

7 Nicholson AG, Magkou C, Snead D, et al. Unusual sclerosing haemangiomas and sclerosing haemangioma-like lesions, and the value of TTF-1 in making the diagnosis. Histopathology 2002; 41:404-13

8 Oliveira P, Moura Nunes JF, Clode AL, et al. Alveolar adenoma of the lung: further characterization of this uncommon tumour. Virchows Arch 1996; 429:101-8

9 Shiota Y, Matsumoto H, Sasaki N, et al. Solitary bronchioloalveolar adenoma of the lung. Respiration 1998; 65:483-5

10 Yousem SA,Hochholzer L Alveolar adenoma. Hum Pathol 1986; 17:1066-71

This page last revised 31.3.2005.

©SMUHT/PW Bishop