Basophilia


Article Author:
Kristin Sticco


Article Editor:
David Lynch


Editors In Chief:
William Gossman


Managing Editors:
Avais Raja
Orawan Chaigasame
Carrie Smith
Abdul Waheed
Khalid Alsayouri
Kyle Blair
Trevor Nezwek
Radia Jamil
Erin Hughes
Patrick Le
Anoosh Zafar Gondal
Saad Nazir
William Gossman
Hassam Zulfiqar
Navid Mahabadi
Hussain Sajjad
Steve Bhimji
Muhammad Hashmi
John Shell
Matthew Varacallo
Heba Mahdy
Ahmad Malik
Sarosh Vaqar
Mark Pellegrini
James Hughes
Beata Beatty
Daniyal Ameen
Altif Muneeb
Beenish Sohail
Nazia Sadiq
Hajira Basit
Phillip Hynes
Komal Shaheen
Sandeep Sekhon


Updated:
12/19/2018 6:20:25 AM

Introduction

Basophils are typically the least numerous myeloid cells seen in a peripheral blood smear. Their numerous dark azurophilic granules easily distinguish them.[1] Basophilia is not a common finding in peripheral blood. Most commonly, it is a reactive mechanism often seen in combination with eosinophilia and an absolute basophil count of greater than 200 cells/uL. Different ranges are set depending on the laboratory and also based on the local population. If performed, bone marrow aspirates may show an increase in basophils or precursors.

Basophils express CD45 and are positive for myeloid markers CD13, CD11b, and CD33. They also express CD22 (also positive in B-cells), bright CD38, and bright CD123.[2]

Etiology

Elevation of basophils may represent an underlying neoplasm such as chronic myeloid leukemia (CML), polycythemia vera (PV), primary myelofibrosis, essential thrombocythemia, acute myeloid leukemia, or rarely solid tumors. More common causes include allergic reactions or chronic inflammation related to infections (including influenza and tuberculosis), inflammatory bowel disease, and autoimmune disease. Drug-related causes and food ingestion also correlate with symptoms and degree of basophilia.[3]

Epidemiology

Basophilia is a condition that does not have a gender predilection but rather, depending on the etiology, will have a specific frequency.

Histopathology

Often, peripheral blood review is required to interpret the cause of basophilia. The most striking feature in basophils is the markedly intense azurophilic granules with dark blue segmented nuclei.[1][3][4]

While basophilia usually presents as a non-specific finding under microscopic exam, the presence of other findings may suggest the need for additional workup. For example, the basophilia in the setting of left-shifted neutrophilia should raise the concern for a myeloproliferative neoplasm, especially CML.  The presence of basophilia with circulating blasts suggests the possibility of acute myeloid leukemia. Review under oil immersion is usually required to avoid misclassifying degranulated basophils, which may resemble hypogranular neutrophils.

History and Physical

The clinical presentation of basophilia is diverse and related to the underlying cause. If splenomegaly is present, a myeloproliferative syndrome may be suspected. Constitutional symptoms such as fever, malaise, itching, and fatigue may be present. Right upper quadrant pain may be present. In polycythemia vera, often erythromelalgia, or burning of the palms and soles, is common. Pruritus post warm shower can be a symptom as well.[3] However, these patients usually present with far more severe symptomatology such as thrombosis. In cases of underlying allergic or hypersensitivity reactions, skin rashes may be present.  

For examination of splenomegaly, a patient should be in the supine position with a relaxed abdomen. The examiner should try and insert 3 fingers into Traube's space (underneath the left side of the rib cage) during inspiration. Another technique which is also sensitive is an ultrasound examination which can lead to the same results.[1][2]

If there is concurrent eosinophilia greater than 1500 cells/uL, hypereosinophilic syndrome may be considered. Symptomatology and other systemic manifestations will be related to skin or pulmonary involvement.

Evaluation

The next step is the peripheral blood smear and evaluation. When there is unexplained left shifted neutrophilia with basophilia, cytogenetic testing is indicated to rule out CML. FISH for BCR-ABL1 fusion may be performed on peripheral blood and, if positive, supports the diagnosis of CML. The other major myeloproliferative neoplasms (PV, PMF, ET) often harbor mutations other mutations. Janus kinase 2 (JAK2) which is an acquired genetic mutation is found in the vast majority of patients with PV, over 50% of patients with primary myelofibrosis and essential thrombocythemia. A minority of patients with ET or PMF will have mutations in either CALR or MPL. The finding of one of these mutations is not specific for a myeloproliferative neoplasm and must be correlated with morphology and clinical findings.

When a bone marrow biopsy is performed for a suspected myeloid neoplasm, cytogenetic analysis is required. This is where the karyotype or the genetic screen of chromosomes of each WBC is tested. Significant abnormalities of in a conventional karyotype support the diagnosis of a neoplastic process. FISH may be performed concurrently to expedite the identification BCR-ABL fusion in a case of suspected CML.[5][3][6]

Treatment / Management

The underlying condition will determine what treatment is appropriate. In those cases associated with allergies or chronic inflammation, treating the underlying cause is critical. Allergic reaction treatments include cessation of the offending agent and treatment with antihistamines. Parasitic infections should be treated with concomitant therapy such as albendazole.[3] Discussion of treatment associated with underlying neoplasia is beyond the scope of this chapter.

Differential Diagnosis

Toxic neutrophils may have azurophilic granules and be rarely mistaken for basophils. However, the granules in neutrophils are much smaller and are often accompanied by Dohle bodies, which are not seen in basophils.

Prognosis

Basophilia, depending on the etiology, has a good prognosis. Infection-related basophilia is treated with antibiotics to treat the underlying cause, whereas neoplasm related basophilia may have a more complicated clinical course.

Treatment of CML includes chemotherapeutic drugs such as imatinib and other modalities for treatment whereas PV and ET required aspirin therapy and intermittent phlebotomy. Overall survival for these patients depends on the degree of care, the persistence of patient follow-up,[7][3] and methods used to prevent thrombotic complications.

Complications

Complications of basophilia are not so much as in the increase in basophils but rather related to the underlying condition. Basophils themselves can degranulate in nascent tissue causing local damage, and it is important to prevent such damage by early intervention. Other complications of basophilia related to CML, PV, or ET include thrombosis both arterial and venous in which patient should have adequate screening and preventative measures.[3]

Pearls and Other Issues

  • Any patient with chronic anemia with a rise in basophils for longer than 6 months should be worked up for an underlying cause.
  • Patients with basophilia should be worked up for CML or AML when no other systemic infection or possible drug-related cause fits.
  • Always rule out drug ingestion and parasitic infection.
  • On a peripheral blood smear look for clues of underlying neoplasia (left shifted neutrophilia or circulating blasts).

Enhancing Healthcare Team Outcomes

When neoplasia is suspected in the setting of basophilia, the pathologist should contact the clinical team. Recommendations should be clearly communicated and should reflect the peripheral smear findings.  For example, if there is unexplained basophilia with left-shifted neutrophilia, the pathologist may recommend that the clinician order BCR-ABL1 FISH to rule out CML.


  • Image 7114 Not availableImage 7114 Not available
    Contributed by David Lynch MD
Attributed To: Contributed by David Lynch MD

Interested in Participating?

We are looking for contributors to author, edit, and peer review our vast library of review articles and multiple choice questions. In as little as 2-3 hours you can make a significant contribution to your specialty. In return for a small amount of your time, you will receive free access to all content and you will be published as an author or editor in eBooks, apps, online CME/CE activities, and an online Learning Management System for students, teachers, and program directors that allows access to review materials in over 500 specialties.

Improve Content - Become an Author or Editor

This is an academic project designed to provide inexpensive peer-reviewed Apps, eBooks, and very soon an online CME/CE system to help students identify weaknesses and improve knowledge. We would like you to consider being an author or editor. Please click here to learn more. Thank you for you for your interest, the StatPearls Publishing Editorial Team.

Basophilia - Questions

Take a quiz of the questions on this article.

Take Quiz
Which of the following disorders is frequently associated with basophilia?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
What is a potential cause of chronic basophilia?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
What cluster of differentiation markers are associated with basophils?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
What is the best initial step in the workup of a patient with chronic basophilia?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 70-year-old female presents to her primary care provider with asthenia that has become worse over the last 5 months. She has a history of acute monoblastic leukemia (AML-M5a) treated with anthracycline-based treatment. At the time of diagnosis, her blood tests showed a hemoglobin level of 8.3 grams/dL, 140 × 109/L platelets, 3.11 × 109/L leukocytes, with 1.19 × 109/L neutrophils, 1.67 × 109/L lymphocytes, 0.060 × 109/L monocytes, 0.16 × 109/L basophils, and 43% blasts. The basophils had coarse granules and vacuoles. Their immunophenotype was CD34+, CD117+, CD33+, CD13+, CD25-/+, CD123+ by flow cytometry. Tryptase was high on serum and histamine as well. What cytogenetic finding is expected?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up

Basophilia - References

References

Boiten HJ,de Jongh E, Atypical basophilia. Blood. 2018 Aug 2     [PubMed]
Han X,Jorgensen JL,Brahmandam A,Schlette E,Huh YO,Shi Y,Awagu S,Chen W, Immunophenotypic study of basophils by multiparameter flow cytometry. Archives of pathology & laboratory medicine. 2008 May     [PubMed]
Valent P,Sotlar K,Blatt K,Hartmann K,Reiter A,Sadovnik I,Sperr WR,Bettelheim P,Akin C,Bauer K,George TI,Hadzijusufovic E,Wolf D,Gotlib J,Mahon FX,Metcalfe DD,Horny HP,Arock M, Proposed diagnostic criteria and classification of basophilic leukemias and related disorders. Leukemia. 2017 Apr     [PubMed]
Tanaka Y,Tanaka A,Hashimoto A,Hayashi K,Shinzato I, Acute Myeloid Leukemia with Basophilic Differentiation Transformed from Myelodysplastic Syndrome. Case reports in hematology. 2017     [PubMed]
Valent P,Horny HP,Arock M, The underestimated role of basophils in Ph{sup}+{/sup} chronic myeloid leukaemia. European journal of clinical investigation. 2018 Oct     [PubMed]
Zhou J,Papenhausen P,Shao H, Therapy-related acute myeloid leukemia with eosinophilia, basophilia, t(4;14)(q12;q24) and PDGFRA rearrangement: a case report and review of the literature. International journal of clinical and experimental pathology. 2015     [PubMed]
Pastoret C,Houot R, "Chronic myelogenous leukemia in primary blast crisis" rather than "de novo {i}BCR-ABL1{/i}-positive acute myeloid leukemia". Clinical case reports. 2017 Jun     [PubMed]

Disclaimer

The intent of StatPearls is to provide practice questions and explanations to assist you in identifying and resolving knowledge deficits. These questions and explanations are not intended to be a source of the knowledge base of all of medicine, nor is it intended to be a board or certification review of Pathology-Molecular Genetic. The authors or editors do not warrant the information is complete or accurate. The reader is encouraged to verify each answer and explanation in several references. All drug indications and dosages should be verified before administration.

StatPearls offers the most comprehensive database of free multiple-choice questions with explanations and short review chapters ever developed. This system helps physicians, medical students, dentists, nurses, pharmacists, and allied health professionals identify education deficits and learn new concepts. StatPearls is not a board or certification review system for Pathology-Molecular Genetic, it is a learning system that you can use to help improve your knowledge base of medicine for life-long learning. StatPearls will help you identify your weaknesses so that when you are ready to study for a board or certification exam in Pathology-Molecular Genetic, you will already be prepared.

Our content is updated continuously through a multi-step peer review process that will help you be prepared and review for a thorough knowledge of Pathology-Molecular Genetic. When it is time for the Pathology-Molecular Genetic board and certification exam, you will already be ready. Besides online study quizzes, we also publish our peer-reviewed content in eBooks and mobile Apps. We also offer inexpensive CME/CE, so our content can be used to attain education credits while you study Pathology-Molecular Genetic.