Malignant lymphomas and related conditions involving nasal cavity and paranasal sinuses: a clinicopathologic study of forty-two cases with emphasis on prognostic factors.

Lymphoproliferative diseases involving the nasal cavity and paranasal sinuses are uncommon and show complex histology, which make our understanding of the disease inadequate. In the present study, clinicopathologic findings, especially prognostic factors, in 42 patients with such diseases were reviewed. Histologically these cases were divided into ordinary lymphoma (23 cases) and a disease pattern that frequently showed a polymorphous picture containing large atypical cells with a non-lymphoid appearance (19 cases). The latter was termed midline malignant reticulosis (MMR) according to Kassel's classification. Clinically 'MMR' showed greater incidence of early onset of disease and higher male preponderance than ordinary lymphoma. The most common presenting symptom was nasal obstruction in both diseases. Favourable prognostic factors assessed by Cox's multivariate analysis were ordinary lymphoma (vs MMR), stage I disease, absence of ulceration in the lesions, and a tendency for local tumor formation.