ABSTRACT
This chapter reviews the current knowledge on rare extranodal presentations of non-Hodgkin’s lymphomas (NHL). Renal involvement is a common finding in patients with advanced NHL and the reported frequency is very high, ranging from 37 to 47%. Primary bladder lymphoma is a rare condition, accounting for only 0.2% of extranodal lymphomas. The incidence of primary lymphomas appearing in rare extranodal sites showed a significant increase after the acquired immuno-deficiency syndrome epidemics, especially regarding aggressive lymphomas; nevertheless, their incidence is still considered very low. Primary adrenal lymphoma is an aggressive disease and should be approached accordingly. Symptoms of adrenal insufficiency such as vomiting, fatigue, skin hyperpigmentation, and hypotension are also frequent. Primary urethral lymphomas show similar clinical and pathological findings to primary bladder lymphomas, including: female predominance; and presentation as a polypoid mass. Primary lymphomas of the renal pelvis and ureters are a rarity among rare diseases.
