Retroperitoneal fibrosis due to B-cell non-Hodgkin lymphoma: Responding to rituximab!

Retroperitoneal fibrosis is a rare disease manifesting as chronic soft tissue fibrosis in the retroperitoneum, with potential anatomic and/or functional compromise of adjacent organs. It can be primary (idiopathic) or secondary to other conditions such as cancers, autoimmune disorders, or drugs. We report herein a 66-year-old patient with symptomatic retroperitoneal fibrosis leading to bilateral hydronephrosis and renal failure, in whom, after a complex diagnostic work-up and protracted clinical course, a B-cell non-Hodgkin lymphoma in the retroperitoneal space and several vertebral bodies was identified. The patient was treated with radiation therapy and weekly rituximab infusions, with resolution of hydronephrosis and lower back pain. We include a thorough literature review on etiopathogenesis, diagnosis, therapy, and prognosis of retroperitoneal fibrosis. A meticulous search for malignancy is necessary in this rare condition that, if positive, may have significant therapeutic and prognostic implications.

An unusual presentation of Kikuchi-Fujimoto disease.

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare, self-limited disease of unknown etiology. This condition is most commonly encountered in Asian and Caucasian females of childbearing age who usually present with cervical lymphadenopathy and fever. Though rarely, KFD has been described in younger African-American females as well. It often mimics more serious conditions such as lymphoma, metastatic solid malignancy, HIV infection, tuberculosis, sarcoidosis, or systemic lupus erythematosus. Although its etiopathogenesis has not been fully elucidated, literature suggests viral or possibly autoimmune components to play a role. We describe a 34-year-old African-American female who presented with constitutional symptoms and polyadenopathy on clinical examination and imaging, of which the portacaval and portahepatis lymph nodes were most prominent. An extensive workup was otherwise unremarkable, and biopsy showed histiocytic necrotizing lymphadenitis. Initially, her clinical condition improved spontaneously, and she required only a short course of oral steroids. Three months later, she relapsed with bilateral cervical adenopathy and constitutional symptoms and was successfully managed again with steroids. Our case is unique with respect to (a) portahepatis and portacaval node enlargement as the dominant adenopathy and (b) her underlying conditions of fibromyalgia and chronic fatigue syndrome.

Collision tumors: pancreatic adenocarcinoma and mantle cell lymphoma.

CONTEXT: Collision tumors are very rare entities composed of two or more distinct tumor components, each separated by normal tissue. Perhaps due to technical advances in the last decade, the incidence of collision tumors has been on the rise. To the best of our knowledge, collision tumors featuring mantle cell lymphoma and pancreatic adenocarcinoma have not been previously described in the scientific literature. CASE REPORT: For the first time, we describe herein the clinical course of a collision tumor between pancreatic adenocarcinoma and mantle cell lymphoma. DISCUSSION: We hypothesize several aspects in the pathogenesis of a such event and review the existing literature on collision tumors.