Abstract
RATIONALE: Liposarcoma, the most common type of soft tissue sarcoma, typically occurs in the deep soft tissues of the limbs and retroperitoneum and is rarely found in the breast. The fifth edition of the World Health Organization classifies it into 5 distinct histological subtypes. Given the rarity of liposarcomas in breast tissue, there remain certain challenges in diagnosis and treatment planning. In this report, we present a rare case of an atypical lipomatous tumor/well-differentiated liposarcoma in breast tissue. PATIENT CONCERNS: A 65-year-old female patient with an asymptomatic movable mass in the left breast was admitted to our hospital. The mass persisted for approximately half a month. Clinical examination and ultrasound examination revealed that the mass within the fatty layer of the left breast was approximately 7.0 cm × 7.0 cm and relatively well circumscribed. DIAGNOSES: The preoperative tests led to a preliminary diagnosis of lipoma; therefore, the patient underwent mass resection of the left breast under local anesthesia. Postoperative pathological analysis indicated a diagnosis of atypical lipomatous tumor/well-differentiated liposarcoma. INTERVENTIONS: Considering the lower malignancy of this pathological type, we performed radical surgical excision and followed the patient for 3 months after surgery. OUTCOMES: No significant signs of recurrence or metastasis were detected during the time. LESSONS: Liposarcoma is rarely found in breast tissue. Moreover, it is difficult to distinguish between lipomas and liposarcomas by assistant examination. In this case report, we sought to enhance the awareness and understanding of breast liposarcoma. Understanding the clinical and pathological characteristics of this rare disease will aid clinicians in better recognition and diagnosis in future clinical practice, as well as in exploring more comprehensive and precise treatment plans and prognosis evaluation systems.