Spontaneous Remission of Blastic Plasmacytoid Dendritic Cell Neoplasm: A Case Report.

Spontaneous remissions (SRs) in blastic plasmacytoid dendritic cell neoplasms (BPDCNs) are infrequent, poorly documented, and transient. We report a 40-year-old man presenting with bycitopenia and soft tissue infection. The bone marrow exhibited 3% abnormal cells. Immunophenotyping of these cells revealed the antigens CD45+ (dim), CD34+, CD117+, CD123+ (bright), HLA-DR+ (bimodal), CD56+ (bright), CD33+, CD13+, CD2+, and CD22+ (dim) and the partial expression of the CD10+, CD36+, and CD7+ antigens. All other myeloid, monocytic, and lymphoid antigens were negative. Genetic studies showed a complex karyotype and mutations in the TP53R337C and KRASG12D genes. On hospital admission, the patient showed a subcutaneous nodule on the right hand and left lower limb. Flow cytometry multiparameter (FCM) analysis showed the presence of 29% abnormal cells with the previously described immunophenotype. The patient was diagnosed with BPDCN. The patient was treated with broad-spectrum antibiotics for soft tissue infection, which delayed therapy for BPDCN. No steroids or chemotherapeutic or hypomethylating agents were administered. His blood cell counts improved and skin lesions disappeared, until the patient relapsed five months after achieving spontaneous remission. About 60% of abnormal cells were identified. No changes in immunophenotype or the results of genetic studies were observed. The patient underwent a HyperCVAD chemotherapy regimen for six cycles. Consolidation therapy was performed via allogeneic bone marrow transplantation with an HLA-unrelated donor. One year after the bone marrow transplant, the patient died due to the progression of his underlying disease, coinciding with a respiratory infection caused by SARS-CoV-2. In the available literature, SRs are often linked to infections or other stimulators of the immune system, suggesting that powerful immune activation could play a role in controlling the leukemic clone. Nevertheless, the underlying mechanism of this phenomenon is not clearly understood. We hypothesize that the immune system would force the leukemic stem cell (LSC) to undergo a state of quiescence. This loss of replication causes the LSC progeny to die off, resulting in the SR of BPDCN.

Unraveling TAFRO Syndrome: An In-Depth Look at the Pathophysiology, Management, and Future Perspectives.

TAFRO syndrome is a rare and aggressive inflammatory entity characterized by thrombocytopenia, anasarca, fever, renal failure, reticulin fibrosis, and organomegaly. This entity supposes a diagnostic and therapeutic challenge due to its significant overlap with Castleman's disease. However, distinct clinical and histological features warrant its classification as a separate subtype of idiopathic multicentric Castleman's disease (iMCD). While recent modifications have been made to the diagnostic criteria for iMCD, these criteria lack specificity for this particular condition, further complicating diagnosis. Due to its inflammatory nature, several complex molecular signaling pathways are involved, including the JAK-STAT pathway, NF-kB, and signal amplifiers such as IL-6 and VEGF. Understanding the involvement of immune dysfunction, some infectious agents, genetic mutations, and specific molecular and signaling pathways could improve the knowledge and management of the condition, leading to effective treatment strategies. The current therapeutic approaches include corticosteroids, anti-IL6 drugs, rituximab, and chemotherapy, among others, but response rates vary, highlighting the need for personalized strategies. The prognosis is uncertain due to diagnostic difficulties, emphasizing the importance of early intervention and appropriate targeted treatment. This comprehensive review examines the evolving landscape of TAFRO syndrome, including the pathophysiology, diagnostic criteria, treatment strategies, prognosis, and future perspectives.

Association of both BCL2 positive and negative follicular lymphoma to clasical Hodgkin lymphoma and/or gray zone lymphoma.

We present a series of 9 follicular lymphomas that progressed/transformed into classical Hodgkin lymphoma (CHL). Three cases of CHL showed a syncytial pattern (SCHL) making the differential diagnosis to Gray zone lymphoma (GZL) challenging. None of these three cases presented in the mediastinum. Based in all molecular data analyzed (BCL2/BCL6 FISH studies, IgH PCR and TNGS with a customized gene panel) we did find clonal relationship between the BCL2-positive FL cases and their CHL components in all cases. The three SCHL/GZL cases showed an activated phenotype according to Hans algorithm, presented the t(14; 18)(q32; q21), two out of three showed B cell markers and all expressed CD30 and p53. Interestingly, we identified three BCL2-negative FL cases with a further diagnosis of CHL expanding the spectrum of these association. In one of these three cases a different mutational profile was found in both the FL and the CHL components. All this data together suggests that CHL associated to BCL2-positive FL could be originated in a common progenitor cell (CPC) that give rise to both FL and CHL, acquiring this last component further genetic events in a linear fashion. On the other hand, no clonal relationship between CHL and BCL2-negative FL could be found, suggesting a fortuity association. Nevertheless, ample series of cases studied with more sensitive techniques are needed to confirm our hypothesis.