Breast Myofibroblastoma during Pregnancy: A Challenging Diagnosis with Delayed Management and Review of the Literature

We report a rare case of breast myofibroblastoma diagnosed during the third trimester of pregnancy in a 32-year-old gravida 3 para 2 woman who presented with a progressively enlarging exophytic nipple mass. Breast ultrasound revealed a heterogeneous, vascularized lesion measuring 55 × 48 mm, classified as BIRADS 4C. Ultrasound-guided core needle biopsy demonstrated a spindle-cell mesenchymal proliferation with strong desmin positivity, focal CD34 expression, and absence of epithelial marker expression, confirming the diagnosis of myofibroblastoma. Considering the confirmed benign histology and advanced gestational age, surgical excision was deferred until the postpartum period to minimize maternal and fetal risks associated with late-pregnancy surgery. Close clinical surveillance was maintained throughout the remainder of the pregnancy. Definitive surgical management was scheduled six months after delivery to ensure optimal operative conditions and complete maternal recovery. This case highlights the diagnostic complexity of spindle-cell breast lesions during pregnancy and emphasizes the importance of multidisciplinary decision-making in balancing oncologic safety with maternal–fetal well-being.