Can Diagnostic Low-dose Whole-body CT Reflect Bone Marrow Findings in Systemic Mastocytosis?

Abstract

Systemic mastocytosis (SM) is a heterogeneous hematological entity, characterized by the proliferation of mast cells, commonly involving the skeleton. The present study sought to elucidate whether the computed tomographic (CT) number as Hounsfield units (HU) derived from whole-body CT is associated with bone marrow findings in SM. Patient records of the local Oncology and Hematology Department from 2007 to 2018 were screened for patients with SM. Total 16 patients [five female (31.2%)] with a mean age of 55.7±10.3 years were included in the present retrospective study. KIT mutation; tryptase, alkaline phosphatase, and calcium level in serum; and the proportion of mast cells, and CD2, CD25- and CD117-positive cells in bone marrow biopsies were evaluated. HU correlated with serum calcium level (r=-0.51, p=0.04), mast cell proportion (r=0.66, p=0.01) and with the proportion of CD117-positive cells in bone marrow biopsy (r=0.56, p=0.04). In the group with aggressive SM, the mean HU value was statistically significantly higher than that of the indolent title:group [245±127 (range=100-451) vs. 121±16 (range=90-135), respectively, p=0.04]. The present study identified that the HU value derived from low-dose CT was associated with mast cell infiltration in bone marrow in SM and with the proportion of CD117-positive cells. Further studies are needed to determine whether the measurement of the HU value has prognostic implications in SM and can be used as a reliable biomarker in this disease.