Mucous gland adenoma, bronchial cystadenoma, mucous gland adenoma, polyadenoma, bronchial adenoma of mucous glands

Definition

A benign exophytic tumour of tracheobronchial seromucinous glands with mucus-filled cysts, tubules, glands and papillae lined by an epithelium that varies from columnar to flattened, with goblet cells, oncocytic cells and clear cells.

Epidemiology

This is a very rare tumour occurring from childhood to old age.

Clinical features

Patients usually present with features of obstruction.

Radiology

The tumour is usually central but may be peripheral, forming a "coin lesion". CT may show an air-meniscus sign.

Macroscopic appearances

The cut surface is mucoid, solid or cystic1.

Histopathology

The tumour is predominantly superficial to the bronchial cartilage. It consists of numerous mucin-filled cysts and non-dilated acini, glands, tubules and papillae1. The cells vary from columnar to cuboidal to flattened. Oncocytic2 or clear cells may occur. Very limited squamous metaplasia may be present2. There may be bands of spindle-cell stroma with hyalinisation or a lymphoplasmacytic infiltrate.

Immunohistochemistry

	epithelial cells	myoepithelial cells
cytokeratins	positive	focally positive
EMA	positive
CEA	positive
SMA		positive
S-100		positive

Ultrastructure

Mucinous and myoepithelial cells types are present. Some cells may show both secretory granules and features of squamous differentiation such as numerous tonofilaments and desmosomes2.

Differential diagnosis

low grade mucoepidermoid carcinoma: closely mimic, but include squamous and intermediate cells.
Mucinous cystadenoma: a peripheral cystic lesion filled with mucin and lined by uniform bland mucinous cells.
Adenocarcinoma: infiltrative with cytoplasmic atypia.

Management

Bronchoscopic or sleeve resection.

Prognosis

Benign1

References

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

1England DM,Hochholzer L. Truly benign "bronchial adenoma". Report of 10 cases of mucous gland adenoma with immunohistochemical and ultrastructural findings. Am J Surg Pathol 1995; 19:887-99

2Heard BE, Corrin B, Dewar A. Pathology of seven mucous cell adenomas of the bronchial glands with particular reference to ultrastructure. Histopathology 1985; 9:687-701

This page last revised 31.3.2005.