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.

Forequarter amputation is a rare procedure, performed mainly for patients with malignant bone and soft tissue tumors. The present case involved a 59-year-old man with left scapula chondrosarcoma. Rehabilitation began on the second day after amputation for a left shoulder chondrosarcoma. We performed early mobilization, wound management, mirror therapy for phantom pain, strength training for the remaining muscles, and activities of daily living (ADL)/instrumental ADL (IADL) training for only the remaining upper limb. In addition, we made a shoulder disarticulation prosthesis. Six months after the operation, the International Society of Limb Salvage-Musculoskeletal Tumor Society functional score was 36.7％ for 6 items and 73.3％ for 3 items, while the Disability of Arm, Shoulder and Hand score was 31.7. The patient-reported outcome had a low score because of the lack of an upper limb, including the scapula. However, when he was discharged from the hospital, he gained self-care independence with only the remaining upper limb and resumed fishing as a hobby. We suggest that rehabilitation after forequarter amputation requires careful intervention based on a deep evaluation of the patient's ADL/IADL, hobbies, and quality of life, in accordance with the patient's lifestyle.