Hematological manifestations such as anemia and low platelet counts (thrombocytopenia) can be the initial presentation of systemic mastocytosis (SM), according to a recently published case report in the journal Cureus.
Although the clinical manifestations of SM are varied, most patients initially present with allergic or gastrointestinal symptoms. Though hematological signs such as anemia and thrombocytopenia can also occur, they are less common and, therefore, are harder to diagnose.
“By highlighting an atypical presentation, this study emphasizes the importance of recognizing SM as a potential underlying cause of otherwise unexplained hematologic abnormalities,” the case report’s authors wrote.
The case involved a 42-year-old woman with a history of asthma and depression who initially presented with pneumonia. Shortly after completing antibiotic treatment, she developed swelling in her left leg, which was treated as a skin and soft tissue infection with additional antibiotics.
Soon after, the patient reported severe pelvic pain and was found to have significant anemia. Magnetic resonance imaging (MRI) at the time revealed inflammation and bleeding in the muscles of the lower back and gluteal region. She was diagnosed with infectious muscle inflammation (myositis) and treated with antibiotics and blood transfusions.
Due to the frequent infections in a short period, physicians ordered immunologic tests that revealed low antibody levels. A subsequent bone marrow biopsy showed tissue necrosis with minimal cellularity.
After multiple blood transfusions, the patient’s hematologic parameters returned to normal, and she was discharged — still without a clear diagnosis. Two weeks later, she returned to the emergency department with a bloody cough and ear pain. Examination revealed active bleeding from the ear into her throat and severe anemia. She was started on tranexamic acid to prevent further bleeding and discharged once stabilized.
Further clinical interrogation revealed a history of flushing, prompting KIT mutation testing to rule out SM. However, the results were negative. One week later, the patient presented again with chest pain and patchy skin rashes. A skin biopsy at this point revealed marked mast cell infiltration. However, further immunohistochemical testing was inconclusive.
Read more about SM testing and diagnosis
A month later, another bone marrow biopsy was performed. This time, there was sufficient mast cell infiltration to confirm a diagnosis of SM, supported by elevated serum tryptase levels.
“Early recognition and comprehensive diagnostic testing, including bone marrow biopsy, serum tryptase measurement, and KIT mutation analysis, are essential,” the authors concluded.
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