Giant cell tumor of bone in pregnancy: A case series from the Eastern Asian Musculoskeletal Oncology Group

Giant cell tumor of bone (GCTB) typically affects females of reproductive age and may be discovered during pregnancy. Pregnancy entails adaptations that could foster a microenvironment favorable to tumor growth. Although a few case reports have described aggressive features, larger studies in this setting are lacking. Thus, this study aimed to examine the clinical characteristics, obstetrical context, diagnostic process, therapeutic interventions, and prognostic outcomes of patients with GCTBs who presented during pregnancy. Patients were included if they developed pain or swelling during pregnancy at the site subsequently confirmed as primary or recurrent GCTB by pathology. Information on 8 patients was collected. The median age at presentation was 26.5 years (range, 22 to 37 years). One (1/8) patient experienced preterm delivery, and another (1/8) underwent elective termination of pregnancy before GCTB surgery. The first symptom was reported at a median gestational age of 5 + 6 (range, 2 + 3–20 + 2) by obstetric dating, but the first radiologic evaluations were often delayed. The most common location was the distal femur (3/8). Pathologic fracture occurred in one (1/8) patient, and all lesions showed Campanacci grade 3 features. The median lesion volume was 93.6 cm 3 (range, 4.2–3348.6 cm 3 ; interquartile range, 18.8–789.2 cm 3 ). No pulmonary metastases were initially observed. Therapeutic approaches appeared to be tailored to individual clinical circumstances. No local recurrences developed in any patient with GCTB in the extremities. No malignant transformation occurred in any patient. Except for one (1/8) patient who died of another disease at 2.5-year follow-up, the other 7 patients (7/8) survived, and 6 (6/8) have remained continuously disease-free during a median follow-up of 5.3 years (range, 2.6–9.8 years). Clinicians should be aware of diagnostic imaging and treatment considerations to ensure timely and appropriate care for patients with GCTB during pregnancy. When musculoskeletal symptoms lack an obstetric explanation, prompt imaging might be crucial. For patients with tumors in surgically challenging sites, surveillance before pregnancy may be prudent. Further research is warranted to elucidate mechanisms through which pregnancy-related physiological changes may influence the oncologic behavior of GCTB.