A 57-year-old man was referred to our hospital with complaints of multiple dark red nodules on the scalp for five years. Five years ago, a soy-sized nodule appeared on the scalp without any discomfort and gradually increased in number and size. The patient was sent to the local hospital seven months ago because of blood in the sputum. The biopsy of the lymph nodes behind the left ear showed that it was in line with Castleman disease, plasma cell type (IgG4>50/HPF, IgG4/IgG>40%). Computed tomography (CT) revealed multiple lymphadenopathies, including the right heart-phrenic angle, retroperitoneum, bilateral iliac area, and groin. Bone marrow biopsy was normal. He was diagnosed with Castleman disease (multicentric plasma cell type). Physical examination revealed multiple irregular-shaped, dark-red, soft to fluctuant, well-demarcated plaques on the scalp ranging from 1 to 8 cm in diameter (Figure 1).
Laboratory tests showed a decreased hemoglobin (Hb, 89 g/L; reference range [RR], 115-150 g/L), elevated erythrocyte sedimentation rate (ESR, 111 mm/h; RR, <20 mm/h), increased C-reactive protein (CRP, 70.4 mg/L; RR, 0-8 mg/L) and positive rheumatoid factor (RF, 21.2IU/mL; RR, 0-15 IU/mL). Serum IgG and IgA levels were high (respectively 62.6 g/L; RR, 7.2-16.8 g/L, 8.90 g/L; RR, 0.82-4.53 g/L), whereas IgM level was normal (1.68 g/L; RR, 0.46-3.04 g/L). Protein immunofixation of serum and urine were negative for M-protein. The serum total protein level was increased (99.9g/L; RR, 60-80 g/L), while the albumin decreased (24.2 g/L; RR, 34-48 g/L), and the albumin-globulin ratio was 0.82 (RR, 1-2). Serum levels of IgG4 (943.0mg/dl; RR, 3-201 mg/dl) were also increased. Serum levels of kappa (49.3g/L g/L; RR, 1.7-3.7 g/L) and lambda (23.4g/L; RR, 0.9-2.10g/L) light chain and urine levels of kappa (34.90mg/dL; RR, 1.7-3.7 g/L) and lambda (12.10mg/dL; RR, 0.9-2.10g/L) light chain was all significantly increased. Serum levels of VEGF (264.21pg/mL; RR, 0-142pg/mL) and interleukin-6 (IL-6, 50.23pg/mL; RR<5.9pg/mL) were all markedly increased. Serologic tests for hepatitis virus types B and C, HHV-8, CMV, EBV, ADV, tuberculosis, syphilis, and HIV antibody were all negative. The biopsy of the lymph nodes behind the left ear showed that small lymphocytes of the mantle zones are arranged in concentric rings around the atrophied germinal center, and amounts of plasma cells in the interfollicular region. The immunohistochemistry results are as followed: CD3 (partial +), CD20 (partial +), Ki67 (+), CD38 (+), CD138 (+), Kappa (+), Lambda (+), BCL-2 (perifollicular +), CD21 (dendritic cell+), CD34 (vascular+), IgG (+), IgG4 (+) (Figure 2). The skin biopsy taken from the right ear revealed variable-sized lymphoid follicles, infiltrated neutrophils, and many plasma cells in the dermis. A broad immunohistochemical panel of CD3, CD20, CD38, CD138, IgG, IgG4, CD34, Kappa, Lambda, BCL-2, and Ki-67 was performed (Figure 3). Based on the clinical, laboratory, and pathological findings, the patient was diagnosed with the plasmacytic variant of idiopathic multicentric CD (pMCD). The patient was treated with bortezomib, cyclophosphamide, and dexamethasone, and the cutaneous lesions disappeared after two months.