A case report recently published in Pediatric Blood & Cancer describes a 9-year-old patient who developed systemic mastocytosis (SM) 10 months after being diagnosed with a germ cell tumor.
Germ cell tumors arise from the reproductive cells, which develop into sperm and egg cells.
The report’s authors noted that the patient initially presented with symptoms of premature puberty. She was found to have a large abdominal mass that was later classified as a germ cell tumor.
After being treated with four cycles of chemotherapy, the patient experienced tumor growth. She then underwent surgery to remove the tumor, including removal of one ovary and fallopian tube. Following surgery, she was declared to be in remission.
Ten months later, the patient began experiencing nausea, abdominal pain and a rash. A skin biopsy revealed signs of cutaneous mastocytosis. Genetic testing revealed a D816V mutation in the KIT gene, which is very common in patients with SM. She also had elevated tryptase levels, another potential marker of SM. Further serological and bone marrow testing confirmed the diagnosis.
Read more about SM causes and risk factors
The authors prescribed avapritinib, a KIT inhibitor, which improved her symptoms and tryptase count. However, treatment was discontinued after she experienced a decline in blood cell counts. As a result, her symptoms reappeared and her tryptase levels increased.
The patient then underwent a bone marrow stem cell transplant. Following the procedure she developed graft-versus-host disease, a complication that results when the patient’s immune system rejects the donor’s cells. She was successfully treated, though, achieving resolution of her condition eight months after the stem cell transplant.
“Future studies are needed to understand the pathogenesis in each tissue and to advance therapeutic options for patients,” the authors concluded.
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