TOACS FCPS Station · Gum Involvement in Acute Myelogenous Leukemia

📷 Clinical Photograph – Gingival Infiltration in AML

Clinical photograph showing swollen, erythematous, hypertrophied gums with bleeding – characteristic gingival infiltration by leukemic blasts in acute myelogenous leukemia

Figure 1 · Gingival Infiltration · Acute Myelogenous Leukemia (AML)

🔍 Key clinical features:

✓ Swollen, hypertrophied gums – boggy, erythematous
✓ Bleeding gums – spontaneous or with mild trauma
✓ Leukemic infiltration – blasts infiltrating gingival tissue
✓ Common in monocytic AML – FAB M4/M5, 11q23 rearrangements
✓ Associated with pancytopenia – anemia, thrombocytopenia, neutropenia

📋 Clinical scenario (examiner prompt)

A 4‑year‑old child is brought to the clinic with a 2‑week history of bleeding gums, fever, and fatigue. The mother reports that the child has been pale and bruising easily. On examination, the gums are swollen, erythematous, and hypertrophied, with spontaneous bleeding (see image). There is cervical lymphadenopathy and hepatosplenomegaly. The child appears ill and has a temperature of 39°C.

Swollen, bleeding gums Fever, pallor, easy bruising Lymphadenopathy, hepatosplenomegaly Pancytopenia

🧑‍⚕️ Examiner tasks · TOACS

1. Identify the diagnosis from the clinical image and context.

2. Describe the clinical features (gingival hypertrophy, bleeding, pancytopenia, fever, hepatosplenomegaly).

3. Explain the underlying condition (acute myelogenous leukemia, especially monocytic subtype).

4. Discuss diagnosis and management (CBC, bone marrow, cytogenetics, chemotherapy).

⚠️ Key concept: Gingival hypertrophy and bleeding in a child with pancytopenia is a classic feature of acute myelogenous leukemia (AML), particularly acute monocytic leukemia (FAB M5) and AML with 11q23 (KMT2A) rearrangements. The leukemic infiltration of gums occurs in 10-20% of pediatric AML cases. Chloromas (granulocytic sarcomas) may also occur in other sites. Diagnosis requires bone marrow aspiration/biopsy with flow cytometry and cytogenetics. Treatment is intensive chemotherapy (cytarabine + anthracycline) and, for high-risk features, allogeneic stem cell transplant.

🎯 Expected answers (for examiners)

• Diagnosis: Acute myelogenous leukemia (AML), likely monocytic subtype (M4/M5)
• Clinical features: Gingival hypertrophy and bleeding (leukemic infiltration), fever, pallor, easy bruising (thrombocytopenia), hepatosplenomegaly, lymphadenopathy, pancytopenia
• Pathophysiology: Malignant proliferation of myeloid blasts with monocytic differentiation; gums infiltrated due to monocytic affinity for tissues; associated with 11q23 (KMT2A) rearrangements and t(9;11)
• Diagnosis: CBC (pancytopenia, blasts), bone marrow aspiration/biopsy (≥20% blasts, myeloperoxidase positive, monocytic markers CD13, CD33, CD14, CD64), cytogenetics, FLT3-ITD, NPM1
• Treatment: Induction chemotherapy (cytarabine + anthracycline); high-risk features (11q23, FLT3-ITD, MRD+) → allogeneic stem cell transplant in first remission
• Supportive care: Transfusions, antibiotics for febrile neutropenia, tumor lysis prophylaxis, dental hygiene

📌 Gingival infiltration in AML – key points:
• Incidence: 10-20% of pediatric AML
• Associated subtypes: Monocytic AML (FAB M4/M5), 11q23 (KMT2A)
• Clinical: Swollen, erythematous, hypertrophied gums with bleeding
• Other extramedullary sites: Skin (leukemia cutis), orbit (chloroma), CNS
• Treatment: Systemic chemotherapy (local treatment not needed if systemic response)
• Prognosis: Depends on cytogenetics; 11q23 has higher relapse risk

⚡ Quick FCPS‑style MCQ

A 4-year-old child presents with swollen, bleeding gums, fever, pallor, and pancytopenia. The most likely diagnosis is:

A. Acute lymphoblastic leukemia (ALL) B. Acute myelogenous leukemia (AML) with monocytic differentiation C. Gingivitis D. Hemophilia

📌 Topic summary · Gum Involvement in AML

Condition
Acute myelogenous leukemia (AML)

Subtype
Monocytic (M4/M5), 11q23

Gum features
Swollen, hypertrophied, bleeding

Other extramedullary
Chloroma, leukemia cutis, CNS

Diagnosis
Bone marrow, flow cytometry, cytogenetics

Treatment
Chemotherapy ± stem cell transplant

Feature	AML with Monocytic Differentiation
Definition	AML with ≥20% blasts, monocytic markers (CD14, CD64, CD11b), myeloperoxidase positive
Gingival infiltration	Swollen, erythematous, hypertrophied gums; bleeding; leukemic blasts on biopsy
Cytogenetics	11q23 (KMT2A) rearrangements (e.g., t(9;11)), t(8;16), t(6;11)
Other extramedullary sites	Skin (leukemia cutis), orbit, CNS, lymph nodes, chloromas
Diagnosis	CBC (pancytopenia, blasts), bone marrow aspirate (≥20% blasts), flow cytometry, cytogenetics, FISH, molecular studies
Treatment	Induction: cytarabine + anthracycline; high-risk (11q23, FLT3-ITD, MRD+) → allogeneic stem cell transplant
Prognosis	Variable; 11q23 higher relapse risk; t(8;21) favorable, inv(16) favorable

🩸 TOACS FCPS Station · Gum Involvement in Acute Myelogenous Leukemia

📷 Clinical Photograph – Gingival Infiltration in AML

🧑‍⚕️ Examiner tasks · TOACS

📌 Topic summary · Gum Involvement in AML