Background and Aims：Sarcopenia is associated with autologous hematopoietic stem cell transplantation (auto-HSCT) -related outcomes in patients with malignant lymphoma (ML). The aims of this study were to investigate changes in skeletal muscle mass after auto-HSCT and risk profiles for sarcopenia after HSCT.Methods：We enrolled 25 patients with refractory ML (age, 57 years [20-69 years]；female/male, 11/14；body mass index, 21.7 kg/m2 [18.9-29.6 kg/m2]). Skeletal muscle mass was evaluated using the psoas muscle index (PMI) measured on computed tomography before and after auto-HSCT. In addition, visceral fat area (VFA) was also measured. Independent factors and profiles associated with a decrease in PMI were evaluated using multivariate and decision-tree analyses, respectively.Results：The PMI was significantly decreased after auto-HSCT (p＝0.0288). A logistic regression analysis revealed that the decreases in PMI and VFA were related. According to the decision-tree analysis, the PMI measured prior to auto-HSCT was selected as the initial branch. Of the patients with a PMI of＜3.74 cm2/m2, 84％ showed a decrease in PMI. Of the patients with a PMI of ≥3.74 cm2/m2, the VFA measured prior to auto-HSCT was the second branch. All the patients with a VFA of ≥115.0 cm2 had decreased PMI.Conclusions：We demonstrated that skeletal muscle mass decreased after auto-HSCT in the patients with ML. The patients with either a PMI of＜3.74 cm2/m2 or a VFA of ≥105.0 cm2 before auto-HSCT were at risk of decreased skeletal muscle mass.

Background and Aims：Sarcopenia is associated with autologous hematopoietic stem cell transplantation (auto-HSCT) -related outcomes in patients with malignant lymphoma (ML). The aims of this study were to investigate changes in skeletal muscle mass after auto-HSCT and risk profiles for sarcopenia after HSCT.Methods：We enrolled 25 patients with refractory ML (age, 57 years [20-69 years]；female/male, 11/14；body mass index, 21.7 kg/m2 [18.9-29.6 kg/m2]). Skeletal muscle mass was evaluated using the psoas muscle index (PMI) measured on computed tomography before and after auto-HSCT. In addition, visceral fat area (VFA) was also measured. Independent factors and profiles associated with a decrease in PMI were evaluated using multivariate and decision-tree analyses, respectively.Results：The PMI was significantly decreased after auto-HSCT (p＝0.0288). A logistic regression analysis revealed that the decreases in PMI and VFA were related. According to the decision-tree analysis, the PMI measured prior to auto-HSCT was selected as the initial branch. Of the patients with a PMI of＜3.74 cm2/m2, 84％ showed a decrease in PMI. Of the patients with a PMI of ≥3.74 cm2/m2, the VFA measured prior to auto-HSCT was the second branch. All the patients with a VFA of ≥115.0 cm2 had decreased PMI.Conclusions：We demonstrated that skeletal muscle mass decreased after auto-HSCT in the patients with ML. The patients with either a PMI of＜3.74 cm2/m2 or a VFA of ≥105.0 cm2 before auto-HSCT were at risk of decreased skeletal muscle mass.