David Fajgenbaum, MD, MBA, MSc: Patient Diagnosis

What is the most likely diagnosis for this patient?

This patient interestingly had only a borderline elevated interleukin-6 level. Now, when most physicians and scientists think about Multicentric Castleman Disease, they immediately think about elevated interleukin-6. That’s because a large portion of patients do have elevated interleukin-6. But that’s not the case for everyone. About one-third of patients, and it gets a little bit higher when you find more symptomatic patients, will respond to blockade or neutralization of interleukin-6. Many patients will not have elevated interleukin-6. What this suggests to us is that there are other cytokines playing important roles. Just based on the mildly elevated interleukin-6, we still cannot make a decision that a treatment will work or will not. At this stage, we’re thinking that this patient has idiopathic Multicentric Castleman Disease, and right away we want to go ahead and start targeting this disease head on with treatment.

Multicentric Castleman Disease: Case 2

Garrett is a 47-year old male carpenter who was formerly a Marine, with a 4-week history of fatigue, night sweats, and weight loss. He reported difficulty breathing for 2 weeks, and 1 week of fevers. He also reported that he’s noted fluid in his legs. He presented to the emergency department for a work-up. His past medical history was only notable for Raynaud’s phenomenon. His family history included a mother that died from a myocardial infarction at 71 and a father who died from lung cancer at 61. His physical exam was notable for bilateral cervical and inguinal lymphadenopathy (1-2 cm), moderate edema (10 lb weight gain in past 7 days), and pleural effusions.

Laboratory findings showed anemia (Hgb: 11 gm/dl), low platelets (109k), and elevated alkaline phosphatase levels. The patient was admitted with a presumed viral illness and then moved to MICU when the patient began experiencing severe difficulty breathing, transaminitis, and increased fluid gain (30 lbs). Further testing showed his CRP >300 mg/L, albumin 1.2 g/dL, renal dysfunction, and Hgb trending downward (now 9 gm/dl), and PLTs trending downward (now 35k). His infectious workup was pan-negative, except for possible EBV infection (8/29/10: EBV PCR positive). He was diagnosed with acute EBV mononucleosis early in admission, but the diagnosis was rescinded when he was found to be EBV IgG+. A rheumatology workup was negative except for a positive ANA (1:120).

The patient was started on 125mg BID of solumedrol without improvement. His hematology/oncology workup was notable for: .

• Elevated B-2-microglobulin
• CT scan: diffuse LAD, splenomegaly
• PET: patchy FDG uptake in SI only (while on high dose steroids)
• Normal Igs (IgG: 930, range: 650-2000; IgM 63, range: 40-270; IgA: 202, range: 50-500)
• Normal/moderately elevated IL-6 (6, nml <5)
• No light chain restriction
• Negative SPEP and UPEP

A bone marrow biopsy reported:

• Hypercellular marrow (90%) with myeloid and megakaryocytic hyperplasia, and emperipoesis.
• Small perivascular lymphohistiocytic aggregate
• Reticulin fibrosis was also noted with &ldquo;cytological atypia of the megakaryocyte lineage (FVIII+, CD61+)&hellip;&rdquo;
• &ldquo;increased CD68+ macrophages (10%)&hellip;&rdquo;
• &ldquo;myeloid: erythroid ratio of 6:1&rdquo;
• &ldquo;Large CD34- cKit+ blasts.&rdquo;
• &ldquo;Rare macrophages and megakaryocytes that contain red and white blood cells.&rdquo;

A lymph node biopsy was scheduled to be performed.