About

Samir Kahwash, MD, is associate chief for education at the department of Pathology and Laboratory Medicine at Nationwide Children’s Hospital and a professor of Clinical Pathology at The Ohio State University. His medical expertise includes hematopathology and pediatric pathology, with a particular interest in pediatric lymphomas and leukemias. He serves as the Program Director of the Clinical Pediatric Pathology Fellowship training at Nationwide Children’s Hospital. Dr. Kahwash has directed training and fellowship programs for over 20 years and has contributed to medical education through initiatives such as the Image of the Week educational exercise and an Instagram educational series. His research and review work include involvement in several COG clinical trials related to pediatric hematologic malignancies. His professional affiliations include memberships in the American Society of Clinical Pathology, Society of Pediatric Pathology, and the College of American Pathologists, among others.

Research topics

• Medicine
• Internal medicine
• Pathology
• Immunology
• Oncology
• Surgery
• Pediatrics

Selected publications

• Parvovirus B-19 Induced Anemia in a Heart Transplant Recipient: Report of a Pediatric Case and Brief Review of Literature

  Fetal and Pediatric Pathology · 2026-03-04

  articleSenior author

  This case represents one of the youngest documented pediatric heart transplant recipients with B19V induced anemia, complicated by viral reactivation despite IVIG, leading to a fatal outcome. Continued viral surveillance and individualized management are needed to improve outcomes in this vulnerable population.

  PublisherDOI

• Two Different Pigments in the Peritoneal Fluid of a Child: What Is the Clinical Significance of Each?

  The Journal of Applied Laboratory Medicine · 2025-05-14

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Cytoplasmic Vacuoles in Lymphocytes of a Child with Sialic Acid Storage Disorder

  Ibnosina Journal of Medicine and Biomedical Sciences · 2025-01-30

  articleOpen accessSenior author

  Abstract This is an image-based clinical vignette demonstrating unusual cytoplasmic vacuoles in the lymphocytes in a stained peripheral blood smear from a 6-month-old infant who presented with seizures, hypotonia, and hepatosplenomegaly and was found to have the extremely rare lysosomal disorder, namely, sialic acid storage disease. Although not specific, it is important to recognize this morphologic finding for reflex biochemical and genetic testing.

  PublisherOA PDFDOI

• Congenital Basaloid Linear Nevus in a Six-Month-Old Child

  Ibnosina Journal of Medicine and Biomedical Sciences · 2025-06-06

  articleOpen accessSenior author
  PublisherOA PDFDOI

• UTILIZING TARGETED IMMUNOTHERAPY TO REDUCE ONCOLOGIC CHEMORADIOTHERAPY IN CAYA WITH ADVANCED MB-NHL

  Leukemia Research · 2025-09-01

  article
  PublisherDOI

• Subcutaneous Fat Necrosis of the Newborn

  Ibnosina Journal of Medicine and Biomedical Sciences · 2025-02-17

  articleOpen accessSenior author

  Abstract This is an image-based clinical vignette showing pathologic findings typical of subcutaneous fat necrosis of the newborn (SFNN). The infant—a 15-month-old girl—presented with indurated subcutaneous masses of unknown etiology. This case is a reminder that SFNN, while more common in the newborn period, can occur throughout infancy. It also reminds us that the rare metabolic disorder (Lesch–Nyhan syndrome) may be associated with lesions that can appear somewhat similar under the microscope.

  PublisherOA PDFDOI

• Subcortical bone marrow and deep marrow differences: A comparison in a series of 5 cases.

  PubMed · 2025-08-01

  article1st authorCorresponding

  This manuscript documents examples of bone marrow cores where subcortical spaces are significantly different in comparison with deep core spaces. The differences include significantly higher or lower cellularity in addition to discrepant involvement by malignant processes. While this phenomenon is generally familiar to practicing pathologists, it is not adequately illustrated in the medical literature. Publication of such illustrated examples may help generate more interest in this phenomenon as well as emphasise the constant need for adequate marrow specimens to avoid diagnostic pitfalls.

  Publisher

• Classic Hodgkin Lymphoma With Primary Presentation as Lytic Bone Lesions and Pancytopenia: Report of a Pediatric Case and Review of Literature

  Pediatric and Developmental Pathology · 2025-03-15

  articleSenior authorCorresponding

  In this report, we describe a case of classic Hodgkin lymphoma presenting with lytic bone lesions and pancytopenia, but with no significant lymphadenopathy or mediastinal mass. We report detailed clinical, radiologic, and pathologic findings. We discuss the scant medical literature of similar cases. We conclude that such cases often represent diagnostic challenges at the clinical and microscopic levels. We emphasize that awareness of this rare presentation of Hodgkin lymphoma is key to avoid diagnostic delay or interpretation pitfalls.

  PublisherDOI

• Iron Deficiency Associated Thrombocytosis May Reach Very High Levels in Children and Usually Shows Inverse Correlation with Hemoglobin and MCV: Report of a Pediatric Case and a Brief Literature Review

  Pediatric and Developmental Pathology · 2025-12-18

  articleSenior authorCorresponding

  In this report, we describe the case of a child with iron deficiency anemia associated with markedly elevated platelet count. We provide detailed sequential data showing platelet count correction towards normal levels as anemia improved with treatment. We discuss the association between iron deficiency and thrombocytosis, the role of IL-6, the potential interaction with other variables such as infections and possible serious complications such as thrombosis.

  PublisherDOI

• Post-transplant maintenance with sorafenib is safe and effective in pediatric patients with har FLT3/ITD AML: A report from the Children's oncology group protocol AAML1031

  Blood · 2025-11-03

  article

  Abstract Introduction Patients with acute myeloid leukemia (AML) with an internal tandem duplication mutation of FLT3 (FLT3/ITD) have a high risk of relapse and cure with chemotherapy alone is rare. FLT3 tyrosine kinase inhibitors (TKIs) target the oncogenic FLT3 receptor to improve outcomes in this poor prognosis subset. COG AAML1031 studied the feasibility and efficacy of adding sorafenib to multi-agent chemotherapy in pediatric patients with FLT3/ITD AML and demonstrated improved disease-free survival compared to a similar a cohort of similar FLT3/ITD+ patients who did not receive TKI. The objective of this analysis was to examine the tolerability and efficacy of sorafenib, specifically when added as maintenance after hematopoietic cell transplantation (HCT). Methods On COG AAML1031, pediatric patients with FLT3/ITD AML (high allelic ratio (HAR) >0.4) were eligible to receive sorafenib plus conventional chemotherapy with each treatment course followed by allogeneic HCT. After HCT, patients could reinitiate sorafenib (starting at 100 mg/m2 with predefined escalation/de-escalation) between day +40-100 and receive for one year from restart. Criteria to restart included adequate hematopoietic recovery without evidence of relapse, no acute GVHD and adequate cardiovascular function (shortening fraction > 28%, no severe hypertension). Patients who received at least one dose of sorafenib after HCT were considered exposed. A control cohort was compiled of (1) patients from AAML0531 arm B who received identical chemotherapy, without sorafenib (n=13), (2) patients on AAML1031 with HAR FLT3/ITD who did not receive any sorafenib (n=6), and (3) patients on AAML1031 who only received pre-HCT sorafenib but did not restart after (n=25). All control patients had received allogeneic HCT on study in first remission. Cumulative incidence of relapse (CIR) after HCT was the primary outcome measure. Post-HCT sorafenib was treated as a time-dependent exposure and non-relapse mortality was a competing event. Results The analysis included 74 patients, 30 with post-HCT sorafenib exposure (post-HCT TKI) and 44 control patients (no post-HCT TKI); of the controls, 25 received pre-HCT sorafenib (pre-HCT TKI only) and 19 never received sorafenib (no TKI). Post-HCT TKI patients were more likely to be non-Hispanic white (83% versus 62%, p=0.012), but otherwise demographic, disease and transplant characteristics, as well as follow up time from HCT, were similar between the post-HCT TKI and control groups. Compared to subjects with pre-HCT TKI only, those who received post-HCT TKI were more likely to have received 3 full courses (87% versus 72%, p = 0.09). Median start day of TKI was 74 (range 42-110); one patient relapsed before day 40. The 5-year CIR for those with post-HCT TKI was 21% (95%CI 8-38%) and for controls was 34% (95%CI 21-48%); HR 0.70, p = 0.416. Median time to relapse was longer in patients who received maintenance (4 versus 15 months). 5-year overall survival (OS) also favored receipt of sorafenib, 90% (95%CI 71%-97%) versus 57% (95%CI 41-70%), OS log-rank p value 0.008. In a sensitivity analysis comparing the post-HCT TKI cohort to the cohort that received pre-HCT TKI only, CIR results were similar (HR = 0.67, p = 0.42) as were OS results (log rank p value .001, 5y OS 90% versus 44%). Sorafenib was well tolerated after HCT; 20/30 (66%) patients were able to complete the full year of treatment, although dose reductions compared to initial dose were common (30%, 24%, 15% in cycles 1-3, respectively). Only 1/3 of subjects experienced an AE of any grade in each cycle, none greater that grade 3, except for one grade 4 neutropenia in cycle 2. The most common grade 3 AE was ALT elevation (13%, cycle 1). The cumulative incidence of acute or chronic graft versus host disease (GVHD) was similar among patients who did and did not receive sorafenib, HR = 0.83 (95%CI 0.38-1.78, p=0.63). Conclusions This prospective study of post-HCT sorafenib maintenance therapy in de novo HAR FLT3/ITD+ pediatric AML demonstrated a clinically, but not statistically significant, reduction in relapse risk and an acceptable side effect profile. Patients who received sorafenib also have substantially improved OS but this may be in part due to a favorable clinical status among patients who restart sorafenib. Further work is needed to understand whether its benefit is limited to specific disease subsets and/or those with pre HCT MRD and to clarify the optimal duration of dosing.

  PublisherDOI

Frequent coauthors

• Alan S. Gamis

  Children's Mercy Hospital

  78 shared

• Todd A. Alonzo

  Children's Oncology Group

  75 shared

• Soheil Meshinchi

  71 shared

• Robert B. Gerbing

  Children's Oncology Group

  66 shared

• Susana C. Raimondi

  St. Jude Children's Research Hospital

  61 shared

• Richard Aplenc

  Hospital for Sick Children

  59 shared

• Betsy Hirsch

  University of Minnesota

  58 shared

• Lillian Sung

  Hospital for Sick Children

  56 shared

Labs

• Pathology and Laboratory Medicine at Nationwide Children's HospitalPI

Awards & honors

• Certificate of Merit in Recognition of Outstanding Service a…
• Award of Service in Education, Department of Pathology and L…
• Syrian Medical Association Recognition Award for Outstanding…
• Certificate of Recognition Award for Dedicated Service, Nati…
• Department of Laboratory Medicine "2007 Educator of the Year…