A challenging diagnosis of idiopathic multicentric Castleman disease with complex systemic presentation: A case report

Abstract

Key clinical message: Idiopathic multicentric Castleman disease (iMCD) is challenging to diagnose due to clinical similarities with other conditions, such as Still's disease. Once diagnosed, iMCD may be effectively managed with the anti-interleukin-6 antibody siltuximab.

Abstract: Here, we present the case of a 19-year-old Polish woman with persistent fever and enlarged lymph nodes and whose diagnosis remained inconclusive following initial clinical assessments and extensive laboratory analyses. The patient had subsequent complaints of joint pain and erythema which were suspicious of Still's disease and resolved with treatment with tocilizumab. Later, the progression of symptoms, such as lymphadenopathy, and elevated interleukin-6 levels were consistent with Castleman disease, leading to the diagnosis of idiopathic multicentric Castleman disease seven years after the patient first reported symptoms. Treatment with the anti-interleukin-6 antibody siltuximab resulted in complete symptom resolution and normalization of inflammatory parameters. No adverse events were reported due to treatment with siltuximab.

Keywords: anti‐interleukin‐6 antibody; case report; diagnosis; idiopathic multicentric Castleman disease; siltuximab.

FIGURE 1

High‐resolution CT scans of the chest and abdomen demonstrating contrast‐enhanced lymph nodes at 3 months before the diagnosis of iMCD (A) and 9 months after initiation of siltuximab (B). (A) Demonstrates lymphadenopathy of the paratracheal mediastinal nodes, nodes in the hilum of the lungs, left subclavicular nodes, right supraclavicular nodes, left parasternal nodes, and retrosternal nodes in the anterior mediastinum. Hepatomegaly in the craniocaudal dimension of the right lobe and splenomegaly are also shown. (B) Illustrates partial regression of inflammatory infiltration and complete regression of fluid in the right pleural cavity on both sides of the lungs. Regression of lymphadenopathy of the mediastinal lymph nodes and lymph nodes located within the lungs is also shown. CT, computed tomography; iMCD, idiopathic multicentric Castleman disease.

FIGURE 2

H&E staining of a lymph node from the supraclavicular region performed at the time of iMCD diagnosis, showing a disturbed histological pattern due to expansion of interfollicular areas with a dominant percentage of plasma cells, and attenuated germinal centers (arrow). Interfollicular hyalinization is also shown (star). H&E, hematoxylin and eosin; iMCD, idiopathic multicentric Castleman disease.