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.

©SMUHT/PW Bishop