Myelodysplastic/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U): More than just a "catch-all" term?

Recurrent bilateral adrenal infarction with myelodysplastic/myeloproliferative neoplasm-unclassifiable (MDS/MPN-U): a case report

BACKGROUND

Bilateral adrenal infarction is rare and only a small number of cases have been reported so far. Adrenal infarction is usually caused by thrombophilia or a hypercoagulable state, such as antiphospholipid antibody syndrome, pregnancy, and coronavirus disease 2019. However, adrenal infarction with myelodysplastic/myeloproliferative neoplasm (MDS/MPN) has not been reported.

CASE PRESENTATION

An 81-year-old man with a sudden severe bilateral backache presented to our hospital. Contrast-enhanced computed tomography (CT) led to the diagnosis of bilateral adrenal infarction. Previously reported causes of adrenal infarction were all excluded and a diagnosis of MDS/MPN-unclassifiable (MDS/MPN-U) was reached, which was considered to be attributed to adrenal infarction. He developed a relapse of bilateral adrenal infarction, and aspirin administration was initiated. Partial primary adrenal insufficiency was suspected as the serum adrenocorticotropic hormone level was persistently high after the second bilateral adrenal infarction.

CONCLUSION

This is the first case of bilateral adrenal infarction with MDS/MPN-U encountered. MDS/MPN has the clinical characteristics of MPN. It is reasonable to assume that MDS/MPN-U may have influenced bilateral adrenal infarction development, considering the absence of thrombosis history and a current comorbid hypercoagulable disease. This is also the first case of recurrent bilateral adrenal infarction. It is important to carefully investigate the underlying cause of adrenal infarction once adrenal infarction is diagnosed, as well as to assess adrenocortical function.

Myelodysplastic/myeloproliferative neoplasms-unclassifiable with isolated isochromosome 17q represents a distinct clinico-biologic subset: a multi-institutional collaborative study from the Bone Marrow Pathology Group

Classification of myeloid neoplasms with isolated isochromosome i(17q) [17p deletion with inherent monoallelic TP53 loss plus 17q duplication] is controversial. Most cases fall within the WHO unclassifiable myelodysplastic/myeloproliferative neoplasms (MDS/MPN-U) category. The uniformly dismal outcomes warrant better understanding of this entity. We undertook a multi-institutional retrospective study of 92 adult MDS/MPN-U cases from eight institutions. Twenty-nine (32%) patients had isolated i(17q) [MDS/MPN-i(17q)]. Compared to MDS/MPN without i(17q), MDS/MPN-i(17q) patients were significantly younger, had lower platelet and absolute neutrophil counts, and higher frequency of splenomegaly and circulating blasts. MDS/MPN-i(17q) cases showed frequent bilobed neutrophils (75% vs. 23%; P = 0.03), hypolobated megakaryocytes (62% vs. 20%; P = 0.06), and a higher frequency of SETBP1 (69% vs. 5%; P = 0.002) and SRSF2 (63% vs. 5%; P = 0.006) mutations that were frequently co-existent (44% vs. 0%; P = 0.01). TP53 mutations were rare. The mutation profile of MDS/MPN-U-i(17q) was similar to other myeloid neoplasms with i(17q) including atypical chronic myeloid leukemia, chronic myelomonocytic leukemia, myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis, myelodysplastic syndrome and acute myeloid leukemia, with frequent concomitant SETBP1/SRSF2 mutations observed across all the diagnostic entities. Over a median follow-up of 52 months, patients with MDS/MPN-i(17q) showed a shorter median overall survival (11 vs. 28 months; P < 0.001). The presence of i(17q) retained independent poor prognostic value in multivariable Cox-regression analysis [HR 3.686 (1.17-11.6); P = 0.026] along with splenomegaly. We suggest that MDS/MPN-i(17q) warrants recognition as a distinct subtype within the MDS/MPN-U category based on its unique clinico-biologic features and uniformly poor prognosis.

Development of a myelodysplastic/myeloproliferative neoplasm-unclassifiable in a patient with acute myeloid leukemia: a case report and literature review

Myelodysplastic/myeloproliferative neoplasms (MDS/MPNs) are a heterogeneous group of hematologic malignancies characterized by dysplastic and myeloproliferative overlapping features in the bone marrow and blood. The occurrence of the disease is related to age, prior history of MPN or MDS, and recent cytotoxic or growth factor therapy, but it rarely develops after acute myeloid leukemia (AML). We report a rare case of a patient diagnosed with AML with t(8; 21)(q22; q22) who received systematic chemotherapy. After 4 years of follow-up, MDS/MPN-unclassifiable occurred without signs of primary AML recurrence.

Traipsing Through Muddy Waters: A Critical Review of the Myelodysplastic Syndrome/Myeloproliferative Neoplasm (MDS/MPN) Overlap Syndromes

Myelodysplastic syndrome/Myeloproliferative neoplasms (MDS/MPNs) are molecularly complex, clinically heterogeneous diseases that exhibit proliferative and dysplastic features. Diagnostic criteria use clinical, pathologic, and genomic features to distinguish between disease entities, though considerable clinical and genetic overlap persists. MDS/MPNs are associated with a poor prognosis, save for MDS/MPN with ring sideroblasts and thrombocytosis, which can behave more indolently. The current treatment approach is risk-adapted and symptom-directed and largely extrapolated from experience in MDS or MPN. Gene sequencing has demonstrated frequent mutations involving signaling, epigenetic, and splicing pathways, which present numerous therapeutic opportunities for clinical investigation.

Favorable outcome of a patient with an unclassifiable myelodysplastic syndrome/myeloproliferative neoplasm treated with allogeneic hematopoietic stem cell transplantation

The entity myelodysplastic syndrome/myeloproliferative neoplasm overlap syndrome is characterized by the coexistence of both myeloproliferative and myelodysplastic features in the bone marrow. Risk assessment and treatment recommendations have not been standardized, and clinicians rely on updated patient studies and reviews to make decisions for treatment approaches. Histopathological features have traditionally been important, although in the last decade, several studies have reported mutational profiles of this rare disease. Here, we present a case, wherein the patient presented with leukocytosis and the diagnostic work-up revealed features of myelodysplastic syndrome/myeloproliferative neoplasm overlap syndrome. Mutational profiling revealed mutations in four genes associated with myeloid malignancies, namely, EZH2, CUX1, TET2, and BCOR. After initial therapy with hydroxyurea and interferon-α, the patient underwent allogeneic hematopoietic stem cell transplantation, with reduced intensity conditioning and a matched sibling donor. He had no signs of relapsed disease 2 years after the transplant. Based on the patient outcome, we summarize the diagnostic and therapeutic approaches for patients diagnosed with myelodysplastic syndrome/myeloproliferative neoplasm overlap syndrome, and review the current literature, emphasizing the role of genetic mutations and allogeneic hematopoietic stem cell transplantation. Larger and more detailed clinical studies are strongly needed to optimize and standardize diagnostic and therapeutic approaches for this disease.