Giant lymph node hyperplasia was initially described by Castleman and colleagues [1] in 1956 as a solitary mediastinal lesion. Since then, isolated cases of this rare disease have been reported in other sites [2] and have been described under two clinicopathologic variants: the hyaline vascular type and the plasma cell type. Systemic manifestations such as fever, anemia, increased erythrocyte sedimentation rate, and hypergammaglobulinemia frequently accompany the plasma cell variant and subside after the lesion is removed [3]. We describe a patient successfully treated with surgery alone for Castleman disease associated with renal amyloidosis.

A 48-year-old woman who had had profound and chronic microcytic and hypochromic anemia since 1976 and who was unresponsive to iron therapy was hospitalized for a nephrotic syndrome. Results of a physical examination were normal. Laboratory findings were as follows: erythrocyte sedimentation rate, 105 mm/h; hemoglobin level, 5.3 g/dL; erythrocyte count, 3 x 10¹²/L; mean corpuscular volume, 63.5 microns³; reticulocyte count, 1%; platelet count, 626 000 cells/mm³; serum iron concentration, 6 µmol/L; and ferritin concentration, 402 µg/L. Acute-phase protein levels were markedly elevated. The serum creatinine level was 197 µmol/L; the serum albumin level was 24 g/L; and proteinuria was present at 18 g/d. Results of a bone marrow examination were normal. Examination of a kidney biopsy specimen showed amyloidosis of the AA type. The patient had no history of recurrent infections, chronic inflammatory diseases, autoimmune diseases, or neoplasms. No other specific diagnosis was made. A computed tomographic scan of the abdomen showed a partially calcified mesenteric mass that was lateral to the aorta and thought to represent lymphadenopathy.

Resection of the mass showed a localized plasma-cell variant typical of Castleman disease. Examination of a liver biopsy specimen showed amyloidosis, as did the stomach fibroscopy. One month after surgical resection, the patient's renal function considerably improved. Her serum creatinine level was 110 µmol/L, the nephrotic syndrome had disappeared, and her hemoglobin level was 9 g/dL. Three months later, her renal function was normal, her hemoglobin level was stable, and the acute phase reactant levels had decreased to normal values.

Castleman disease has been associated with renal amyloidosis in very few patients. Nevertheless, the disease should be suspected in all patients presenting with anemia, inflammatory syndromes, and amyloidosis of the AA type. In addition to surgical resection of the tumor, patients may have received such therapies as monoclonal anti-interleukin-6 antibody (BE-8) [4], corticosteroids, and high-dose dexamethasone and have had splenectomy.

In our patient, Castleman disease was associated with renal and extrarenal amyloidosis. The resection of the lymphomatic mass corrected most abnormalities, including the nephrotic syndrome and renal insufficiency. We suggest that surgery should be used in similar cases as the first-line treatment before administration of corticosteroids or any other potentially aggressive drug.