Low-grade sinonasal adenocarcinoma

Definition

These are rare tumours, usually arising in the ethmoid or maxillary sinuses.

Anatomical site

Low grade carcinomas more often occur in the nasal cavity itself, rather than in the sinuses2, unlike high grade sinonasal carcinomas, which usually occur in the sinuses.

Histopathology

The most well-differentiated tumours resemble normal colonic intestinal mucosa. Most tumours are composed of small glands in a back-to-back arrangement. Glands may be cystically dilated or contain papillary projections. Nuclei tend to be uniform and mitoses rare. Necrosis is focal at most2.

Immunohistochemistry

See table for sinonasal adenocarcinoma, intestinal type

Differential diagnosis

Epithelial adenomatoid hamartoma
Salivary gland type tumours
Intestinal type adenocarcinoma
Oncocytic papilloma
Metastatic papillary carcinoma of the thyroid.

Prognosis

Disease is usually localised and the prognosis good. Local recurrences are common but are usually of limited extent and do not involve the central nervous system. However, occasional tumour may prove lethal2.

References

1Perez-Ordonez B. Special tumours of the head and neck. Current Diagnostic Pathology 2003;9:366-383.

2Cathro, H. P. and S. E. Mills (2004). "Immunophenotypic differences between intestinal-type and low-grade papillary sinonasal adenocarcinomas: an immunohistochemical study of 22 cases utilizing CDX2 and MUC2." Am J Surg Pathol 28(8): 1026-32.

This page last revised 10.2.2004.