Multifocal extranodal lymphomas: an expression of homing phenomenon.

The present study analyses 27 patients with primary lymphoma involving multiple extranodal sites. Eight patients were found to have multiple extranodal involvement at presentation while in 19 patients, relapse of disease was noticed at a different extranodal site without any other systemic spread. Malignant lymphomas of Waldeyer's ring were frequently associated with involvement of gastrointestinal, gonadal or cutaneous lesion. Primary gonadal lymphoma also showed a high incidence of cutaneous, pleura and bone involvement. The homing pattern of mucosa-associated lymphoid cells explains the multifocal extranodal lymphomas with site-specific tropism.