Explore case studies of the types of patients you may see in your practice

SM-AHN confirmed on second evaluation

Patient history and presentation:

• Initial signs and symptoms and pathology confirmed Victor's diagnosis of chronic myelomonocytic leukaemia (CMML). At that time, NGS on bone marrow detected TET2, SRSF2, RUNX1 and KIT D816V mutations.
• After initiating first-line therapy with a hypomethylating agent, Victor returned for follow-up due to: unresolved splenomegaly, recent onset of bone pain, worsening fatigue, unexplained weight loss and increased episodes of diarrhoea

Full lab results:

• Complete blood count, chemistry profile and liver function tests: In the normal range
• Follow-up serum tryptase: Persistently elevated at 130 ng/mL
• KIT D816V in peripheral blood with high-sensitivity assay: Positive
• Referred to haematologist/oncologist to conduct bone marrow biopsy. Pathology report revealed ~35% spindle-shaped bone marrow mast cells.

With bone marrow mast cell clusters and a positive KIT D816V mutation, Victor's diagnosis was revised to systemic mastocytosis with an associated haematological neoplasm (SM-AHN), with CMML as the -AHN component

ISM presenting with skin lesions

Patient history and presentation:

• Initially diagnosed with cutaneous mastocytosis (CM) after presenting to a dermatologist with maculopapular lesions on her torso and upper thigh
• Katherine was prescribed topical steroids for a year, but they led to only limited relief
• Referred to an allergist due to new symptoms: headaches, fatigue, diarrhoea, trouble focusing and inability to work. Reported increased frequency of 'flare-ups' and inadequacy of over-the-counter symptomatic medications, such as H1- and H2-blockers.

Full lab results:

• Complete blood count and chemistry profile: In the normal range
• Serum tryptase: Persistently elevated at 110 ng/mL
• KIT D816V in bone marrow with high-sensitivity assay: Reconfirmed positive mutation status
• Immunohistochemistry (IHC) staining for CD25 and CD117 on bone marrow biopsy revealed CD25 spindle-shaped mast cells of >15 cells per cluster, >35% infiltration of cellularity by mast cells.

With persistently elevated serum tryptase, >30% mast cell infiltration in the bone marrow and a positive KIT D816V mutation, Katherine's diagnosis was revised to indolent systemic mastocytosis (ISM)

ISM presenting with recurrent anaphylactic episodes

Patient history and presentation:

• Presented to A&E after going into anaphylactic shock with hypotension from a bee sting
• History of chronic urticaria, managed with high-dose antihistamines
• Reported increased frequency of unexplained anaphylaxis (three episodes in previous month)
• Recent onset of diarrhoea of daily occurrence
• Blood work revealed heightened risk for future anaphylactic episodes with elevated IgE and baseline serum tryptase (106 ng/mL)
• Referred to allergist for suspected mast cell involvement

Full lab results:

From allergist:

• Complete blood count and chemistry profile: In the normal range
• Serum tryptase: Persistently elevated at 110 ng/mL
• Diagnosed with mast cell activation syndrome (MCAS) and referred to a haematologist

From haematologist:

• IHC staining for CD25 and CD117 on bone marrow biopsy revealed CD25 spindle-shaped mast cells of >15 cells per cluster, >35% infiltration of cellularity by mast cells
• KIT D816V in peripheral blood with high-sensitivity assay: Positive

With a positive KIT D816V mutation, >35% infiltration of cellularity by mast cells, aberrant expression of CD25 and irregular, spindle-shaped mast cells, Maria was diagnosed with ISM

ISM presenting with frequent diarrhoea and nausea

Patient history and presentation:

• Presented with diarrhoea, abdominal pain, nausea and weight loss; initially diagnosed with inflammatory bowel disease and managed with corticosteroids
• Returned to gastroenterologist reporting increased diarrhoea and nausea that was preventing him from leaving the house
• Colonoscopy performed for further examination, revealing mucosal nodularity; biopsy showed dense spindle-shaped mast cell infiltration of the lamina propria, suggesting mastocytosis
• Concurrent blood work showed elevated serum tryptase (79.5 ng/mL)
• Referred to a haematologist for suspected mast cell involvement

Full lab results:

From gastroenterologist:

• Complete blood count and chemistry profile: In the normal range
• Serum tryptase: Elevated at 79.5 ng/mL
• Referred to a haematologist to conduct bone marrow biopsy

From haematologist:

• IHC staining for CD25 and CD117 on bone marrow biopsy revealed CD25 spindle-shaped mast cells of >20 cells per cluster, >40% infiltration of cellularity by mast cells
• KIT D816V in peripheral blood with high-sensitivity assay: Positive

With a positive KIT D816V mutation, >40% infiltration of cellularity by mast cells, aberrant expression of CD25 and irregular, spindle-shaped mast cells, Peter was diagnosed with ISM