Mixed squamous cell and glandular papilloma of the lung

Definition

A benign endobronchial tumour showing both squamous and glandular epithelium, of which the latter should constitute at least one third.

Synonym

Transitional cell papilloma.

Epidemiology

These tumours are extremely rare. Smoking may play an aetiological role, but there is no evidence that HPV does so 1.

Clinical features

Presentation is with obstructive symptoms.

Macroscopic appearances

The lesion is polypoidal.

Histopathology

There is a fibrovascular core covered by squamous and glandular epithelium. The squamous epithelium may show atypia1.

Immunohistochemistry

Has not been investigated.

Differential diagnosis

• Inflammatory endobronchial polyps with squamous metaplasia: there is abundant granulation tissue. and a dense lymphoplasmacytic infiltrate.

• Well-differentiated squamous cell carcinoma.

• Papillary variant of mucous gland adenoma: lacks fibrovascular stromal cores.

• Papillary adenomas: are not within airways.

• Papillary adenocarcinoma: shows atypia and invasion.

Management

Resection

Prognosis

Thought to be benign

References

1Flieder DB, Koss MN, Nicholson A, et al. Solitary pulmonary papillomas in adults: a clinicopathologic and in situ hybridization study of 14 cases combined with 27 cases in the literature. Am J Surg Pathol 1998; 22:1328-42

This page last revised 8.4.2005.

©SMUHT/PW Bishop