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Radiologic features of Castleman’s disease occupying the renal sinus
Nishie A., Yoshimitsu K, Irie H, Aibe H, Tajima T, Shinozaki K, Nakayama T, Kakihara D, Naito S, Ono M, Muranaka T, Honda H
From the Department of Clinical Radiology and Urology, Graduate School of Medical Sciences, Kyushu University, Maidashi, Higashi-ku Fukuoka, Department of Radiology Kitakyushu Municipal Medical Center, Kokurakita-ku Kitakyushu and National Kyusyu Medical Center, Chuo-ku Fukuoka, Japan
AJR Am J Roentgenol. 2003; 181: 1037-40

  • Objective: Our purpose was to describe the radiologic findings in five abnormalities in three patients with Castleman’s disease occupying the renal sinus.
  • Conclusion: Common findings such as mild homogeneous enhancement passing through the mass of the collecting system with mild hydronephrosis on contrast-enhanced CT and hypointense signal on T2-weighted images were obtained. Castleman’s disease may be considered in a differential diagnosis of a mass occupying the renal sinus, although it is difficult to differentiate from malignant lymphoma.

Abstract Edited

  • Purpose: To describe the radiologic findings in five abnormalities in three patients with Castleman’s disease occupying the renal sinus.
  • Materials and Methods: We report three patients (two men, one woman; 65 – 73 years old; mean, 69 years old) with proven Castleman’s disease involving the renal sinus. In one patient, the mass was unilateral; in the other two, it was bilateral. All five masses were diagnosed histologically at nephrectomy or open surgical biopsy. The histologic types included the mixed form in one patient and the plasma cell type in the other two patients. No lesions, other than those in the renal sinus, were detected in any patient during a radiologic examination of the entire body. One of the three patients was symptomatic (weight loss); the other two were asymptomatic. CT, MRI and angiographic examinations were performed.
  • Results: The five masses, in three patients, ranged in maximal diameter from 3.0 to 4.5 cm (average diameter, 3.9 cm). All masses had relatively well-defined margins except on the anterior side, where irregular margins were seen. All lesions showed slightly higher attenuation than renal parenchyma on unenhanced CT images and mild homogeneous enhancement on the early phase images. The enhancement persisted to the delayed phase. However, the attenuation of the masses after injection of the contrast agent never approached that of normal renal parenchyma. As a result, all masses showed lower attenuation than renal parenchyma. Moreover, mild hydronephrosis, which was detected as blunting of the calices, was seen in all kidneys associated with a mass in the renal sinus, and the collecting system passed through the masses without being obstructed. On MR imaging, three masses, in two patients, had homogeneous and isohypointense signal relative to that of the renal cortex on T1-weighted images. On T2-weighted images, all masses were homogeneous and hypointense in signal compared with that of the renal cortex. Angiography was performed in one patient. No definite vascular staining was seen at the renal sinus. Both the left renal artery and the left renal vein were patent, and no irregularity of the vascular wall was seen.
  • Conclusion: Common findings such as mild homogeneous enhancement passing through the mass of the collecting system with mild hydronephrosis on contrast-enhanced CT and hypointense signal on T2-weighted images were obtained. Castleman’s disease may be considered in a differential diagnosis of a mass occupying the renal sinus, although it is difficult to differentiate from malignant lymphoma.

  • Editorial Comment
    The abstract of this paper was editorially prepared with the purpose of to call the attention for this relatively uncommon pathological entity, which only recently has been more frequently recognized. Castleman’s disease is an uncommon type of hyperplasia of lymphoid follicles that only sporadically occurs in the abdomen and pelvis. Histologically, this disease can be divided into 3: the hyaline vascular type, which is more common (90% of cases), the plasma cell type and the mixed form. It may present as asymptomatic involvement of one lymph node group (unicentric) or as a multicentric disease with systemic symptoms. Unlike localized disease, for which surgical excision is curative regardless of the histological type, multicentric disease often necessitates aggressive systemic therapy and portends a poor outcome. The most frequently sites of involvement are: chest (67-70%); neck (14-40%); retroperitoneum (paraaortic or pararenal space, 5-9%) and mesentery.
    The most frequent appearance of abdominal or pelvic Castleman disease is of a single, well-defined enhancing mass simulating either bulky adenopathy, primary retroperitoneal tumor or lymphoma. When the mass occurs in the pararenal space can be associated with hydronephrosis. Calcification is seen in about 30% of the cases. Castleman’s disease, although rare, should be included in the differential diagnosis of an isolated well defined solid mass in the retroperitoneum or a soft tissue mass occurring in the renal sinus or in the pararenal space.

Dr. Adilson Prando
Department of Radiology
Vera Cruz Hospital
Campinas, São Paulo, Brazil