Idiopathic Plasmacytic Lymphadenopathy Forms an Independent Subtype of Idiopathic Multicentric Castleman Disease

Abstract

Idiopathic multicentric Castleman disease (iMCD) is a type of Castleman disease that is not related to KSHV/HHV8 infection. Currently, iMCD is classified into iMCD-TAFRO (thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly) and iMCD-NOS (not otherwise specified). The former has been established as a relatively homogeneous disease unit that has been recently re-defined, while the latter is considered to be a heterogeneous disease that could be further divided into several subtypes. In 1980, Mori et al. proposed the concept of idiopathic plasmacytic lymphadenopathy (IPL), a disease presenting with polyclonal hypergammaglobulinemia and a sheet-like proliferation of mature plasma cells in the lymph nodes. Some researchers consider IPL to be a part of iMCD-NOS, although it has not been clearly defined to date. This is the first paper to analyze iMCD-NOS clinicopathologically, to examine whether IPL forms a uniform disease unit in iMCD. Histologically, the IPL group showed prominent plasmacytosis and the hyperplasia of germinal centers, while the non-IPL group showed prominent vascularity. Clinically, the IPL group showed significant thrombocytosis and elevated serum IgG levels compared to the non-IPL group (p = 0.007, p < 0.001, respectively). Pleural effusion and ascites were less common in the IPL group (p < 0.001). The IPL group was more likely to have an indolent clinical course and a good response to the anti-IL-6 receptor antibody, while the non-IPL counterpart frequently required more aggressive medical interventions. Thus, the IPL group is a clinicopathologically uniform entity that forms an independent subtype of iMCD.

Idiopathic multicentric Castleman disease (iMCD)‐idiopathic plasmacytic lymphadenopathy: A distinct subtype of iMCD‐not otherwise specified with different clinical features and better survival

“…The first two sets of criteria do not specify platelet levels; nevertheless, thrombocytosis was indeed more commonly observed in the IPL group under previous criteria. 9,11 In addition, these criteria have stringent requirements for serum IgG levels. In our study, nearly one-third of patients with iMCD-IPL (n = 30) did not meet Kojima et al's definition, mainly because they did not meet the polyclonal hypergammaglobulinaemia criteria.…”

“…In 2022, Nishikori et al 9 . analysed the clinical features of 42 patients with iMCD‐NOS with and without IPL and determined that iMCD‐IPL might form an independent subtype of iMCD.…”

“…In 2022, Nishikori et al 9 analysed the clinical features of 42 patients with iMCD-NOS with and without IPL and determined that iMCD-IPL might form an independent subtype of iMCD. However, the sample size was small, and survival information was not compared between the two groups.…”

Castlemans Disease – Presenting with Recurrent Pleuropericardial Effusions- Mimicking Tuberculosis

“…Histologically, iMCD is sub classified as : plasma cell and hyper vascular types [4] . The mixed type shows features of of both the above subtypes, but there is no clear pathological definition [3] iMCD-TAFRO histo-pathologically associated with the Hyper vascular type, and iMCD-NOS usually associated plasma cell type [3] iMCD-NOS is associated with un-diagnosed, atypical autoimmune diseases, also in [5] conditions causing hypergammaglobulinemia such as infections, hepatitis, collagen diseases, hyperthyroidism, allergic diseases, liver cirrhosis and lymphoma [6] A comprehensive battery of tests is required to diagnose i-MCD namely tests for organ dysfunction [example renal functions, LFT, ECHO, pulmonary function tests] and inflammatory markers [complete blood picture, ESR ]. Pan CT to visualize the extent of disease is indicated.…”

Immune‐mediated thrombocytopenia and IL‐6‐mediated thrombocytosis observed in idiopathic multicentric Castleman disease

“…[6][7][8][9] Without prompt therapy, disease progression in iMCD-TAFRO patients can rapidly escalate to multiorgan dysfunction and death. 10 Other subtypes include idiopathic plasmacytic lymphadenopathy (iMCD-IPL), which involves hypergammaglobulinaemia and thrombocytosis, 11,12 and iMCD-not otherwise specified (iMCD-NOS), which does not meet the criteria for either iMCD-TAFRO or iMCD-IPL. 13 Rather than exhibiting acute, life-threatening symptoms, iMCD-IPL and iMCD-NOS patients tend to experience moderate, persistent symptoms.…”