骨髓软化转变（GTBM）是各种疾病的并发症之一，其中包括厌食症（AN）。我们描述了一例罕见的20岁男性病例，他来我们诊所时主诉脚后跟疼痛已有3个月，无创伤史。初诊时，注意到他的身体质量指数（BMI）为16.2 kg/m²，并有全血细胞减少症。磁共振成像显示左跟骨在T1加权像上呈低信号，T2加权像上呈高信号。考虑到这个病灶可能是淋巴增殖性肿瘤或骨转移瘤中的梁型骨源性肿瘤，我们进行了开放活检。然而，对骨组织样本的组织病理学检查显示脂肪细胞萎缩，伴有明胶状物质沉积和造血细胞数量减少。因此，我们得出了GTBM的诊断，最可能是由AN引起的。我们开始进行营养支持治疗，6个月后，血液学参数恢复正常，BMI改善至19.4 kg/m²。患者能够返回工作，左跟骨疼痛消失。本病例表明，足踝外科医生需要了解这种罕见的病理变化，尽管在未进行活检的情况下可能很难确诊。据我们所知，迄今为止仅有少数几篇关于跟骨GTBM的描述。© 作者们 2023年。

Gelatinous transformation of bone marrow (GTBM) is a complication of various diseases, one of which is anorexia nervosa (AN). We describe a rare case of a 20-year-old man who presented to our clinic with a 3-month history of heel pain without trauma. At presentation, he was noted to have a low body mass index (BMI) of 16.2 kg/m2 and pancytopenia. On magnetic resonance imaging, the left calcaneus showed low intensity on T1-weighted and high intensity on T2-weighted images. Open biopsy was done because we suspected that the lesion was either a lymphoproliferative tumor or a trabecular-type bone metastatic tumor. However, tissue histology of bone samples showed atrophy of fat cells with deposition of gelatinous material and a decreased hematopoietic cell population. Therefore, we made a diagnosis of GTBM, most likely caused by AN. We started treatment with nutritional support, and 6 months later, the hematological parameters returned to normal and BMI improved to 19.4 kg/m2. He was able to return to work and had no left heel pain. This case indicates that foot and ankle surgeons need to be aware of this rare pathology, although it might be difficult to diagnose without biopsy. To our knowledge, very few descriptions of GTBM in the calcaneus have been reported to date.© The Author(s) 2023.