Myeloid Proliferations Associated with Down Syndrome: Clinicopathologic Characteristics of Forty Cases from Five Large Academic Institutions.

INTRODUCTION: The incidence of myelodysplastic syndrome and acute myeloid leukemia is significantly increased in children with Down syndrome (DS). Within the revised 2016 WHO edition, these entities are jointly classified as myeloid leukemia associated with DS (ML-DS). Additionally, infants with DS may develop transient abnormal myelopoiesis (TAM) which is histomorphologically similar to ML-DS. While TAM is self-limiting, it is associated with an increased risk of subsequently developing ML-DS. Differentiating TAM and ML-DS is challenging but clinically critical. METHODS: We performed a retrospective review of ML-DS and TAM cases collected from five large academic institutions in the USA. We assessed clinical, pathological, immunophenotypical, and molecular features to identify differentiating criteria. RESULTS: Forty cases were identified: 28 ML-DS and 12 TAM. Several features were diagnostically distinct, including younger age in TAM (p < 0.05), as well as presentation with clinically significant anemia and thrombocytopenia in ML-DS (p < 0.001). Dyserythropoiesis was unique to ML-DS, as well as structural cytogenetic abnormalities aside from the constitutional trisomy 21. Immunophenotypic characteristics of TAM and ML-DS were indistinguishable, including the aberrant expression of CD7 and CD56 by the myeloid blasts. DISCUSSION: The findings of the study confirm marked biological similarities between TAM and ML-DS. At the same time, several significant clinical, morphological, and genetic differences were observed between TAM and ML-DS. The clinical approach and the differential diagnosis between these entities are discussed in detail.

Transfusion-Associated Circulatory Overload and Transfusion-Related Acute Lung Injury.

OBJECTIVES: To review the new current diagnostic criteria of transfusion-associated circulatory overload (TACO) and transfusion-related acute lung injury (TRALI) from the literature while highlighting distinguishing features. We provide comprehensive understanding of the importance of hemovigilance and its role in appropriately identifying and reporting these potentially fatal transfusion reactions. METHODS: A review of the English language literature was performed to analyze TACO and TRALI while providing further understanding of the rationale behind the historical underrecognition and underreporting. RESULTS: Our review demonstrates the new 2018 and 2019 case definitions for TACO and TRALI, respectively. With more comprehensive diagnostic strategies, adverse transfusion events can be better recognized from mimicking events and underlying disease. In addition, there are mitigation strategies in place to help prevent complications of blood product transfusion, with emphasis on the prevention of TACO and TRALI. CONCLUSIONS: TACO and TRALI are potentially fatal adverse complications of blood transfusion. Both have been historically underrecognized and underreported due to poor defining criteria and overlapping symptomatology. Developing a thorough clinical understanding between these two entities can improve hemovigilance reporting and can contribute to risk factor identification and preventative measures.

Angioimmunoblastic T-cell lymphoma masquerading as granulomatous lymphadenitis: Fine needle aspiration cytology, clinical and radiology correlation.

Fine needle aspiration (FNA) is a minimally invasive technique used in the initial diagnosis of superficial lesions, including lymphadenopathy. Its benefit in lymph node pathology, however, is highly variable, especially in heterogeneous lymphoproliferative disorders like angioimmunoblastic T-cell lymphoma (AITL). AITL is an aggressive hematopoietic malignancy, histologically characterized by medium-sized neoplastic cells, high endothelial venule proliferations, and a heterogeneous hematolymphoid background. Diagnostic difficulty arises at lymph node FNA, where cytology yields nonspecific polymorphous collections of medium-sized lymphocytes, hematolymphoid cells, dendritic cell-lymphoid complexes, and lymphoid tissue fragments with transgressing blood vessels; findings mimicking reactive lymphadenopathy. We present a case of a 62-year-old male who presented with cervical lymphadenopathy. Neck level II lymph node FNA revealed granulomatous inflammation. A cell block was prepared for additional infectious studies but was non-contributory due to lack of material. Flow cytometry showed no evidence of non-Hodgkin lymphoma. Excisional biopsy revealed lymph node effacement by a T-cell lymphoproliferative disorder consistent with AITL. This case contributes to the paucity of literature regarding the cytologic features of AITL observed at FNA, and becomes the premier case to emphasize the addition of granulomatous features. Despite the aggressive nature of this entity, cases are frequently misdiagnosed as reactive on initial evaluation resulting in delay of treatment. This report serves to raise suspicion of AITL and other polymorphic cellular lymphomas in the setting of reactive granulomatous cytomorphology, thus prompting histological examination of tissue biopsy, expediting treatment, and ultimately providing potential improvement to the current prognosis.