Mast Cell Leukemia: An Update with a Practical Review

Treatment refractory mast cell leukemia with dominant gastrointestinal manifestation and concomitant skin symptoms: A case report

BACKGROUND

Mast cell leukemia (MCL), a subtype of systemic mastocytosis (SM), is an extremely rare clinical entity characterized by a very poor prognosis. Chemotherapy, tyrosine kinase inhibitors, and allogeneic hematopoietic cell transplantation are the only treatment options, but they cannot provide the desired outcomes in most cases of MCL. However, other types of SM can be successfully treated. The disease has no specific manifestation, but gastroenterological symptoms are present in most cases.

CASE SUMMARY

The authors, hereby, report a case of a 46-year-old female patient diagnosed with MCL-the rarest subtype of SM. The patient presented to the gastroenterology clinic with multiple, various, and unspecific gastroenterological symptoms. Concomitance of skin lesions significantly contributed to a relatively prompt diagnosis. The serum tryptase level was extremely high and bone the marrow aspirate showed an infiltration of atypical mast cells. The disease was rapidly progressive and primary refractory to chemotherapy and the patient succumbed to the illness about a month after the initiation of treatment.

CONCLUSION

Despite its “hematological nature”, MCL, in most cases presents dominantly with unspecific gastroenterological symptoms. Thus, a high disease awareness among physicians other than hematologists is necessary to improve treatment outcomes. Serum tryptase level, due to its non-invasive nature and easy access, may serve as an initial step to estimate the probability of mastocytosis.

Renal Extramedullary Hematopoiesis in Mast Cell Leukemia with Bone Marrow Fibrosis

Systemic mastocytosis is defined by the clonal proliferation of abnormal mast cells. The clinical course can range from indolent forms with normal life expectancy to advanced mast cell leukemia with dismal prognosis. An association with other diseases, including myeloproliferative neoplasia, has been described. We present a case of a 75-year patient with a history of cutaneous mastocytosis who was diagnosed with mast cell leukemia more than 9 years ago and did not receive treatment. The patient presented to our clinic with acute kidney failure because of renal extramedullary hematopoiesis. Bone marrow histopathology revealed extensive fibrosis and 50% infiltration by mast cells with a c-KIT D816V mutation. No mutations supporting primary myelofibrosis were identified. Treatment with midostaurin was started, and the patient was discharged after improvement of renal function. Here, we discuss diagnostic challenges between different forms of mast cell leukemia and overlaps with other hematological malignancies.