Liposarcoma of the breast is a very rare soft tissue malignant tumor arising in the fat cells, with a prevalence of 0.3% of all malignant breast tumors, clinically manifested as a palpable breast mass mimicking a primary breast cancer. In the present paper, we had two objectives: (i) to report the first liposarcoma case in our Clinic and (ii) to screen the scientific literature on the topic. Our report presents an unusual case of a 56-year-old female with symptomatic left breast mass initially histopathologically diagnosed as a mesenchymal lesion. Four months later, the tumor was histopathologically identified as a grade 3 dedifferentiated liposarcoma (DDLPS) Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC; French Federation of Cancer Centers). We present the histopathological, immunohistochemical, and radiological features of the case and outcomes. Secondly, we performed a systematic search on liposarcoma on the PubMed®∕Medline® and Web of Science® databases, using the keyword "primary breast liposarcoma" (all-time topic). Due to the small number of cases found in the literature, the best treatment choice and determination of prognosis are difficult to make. Our patient underwent breast radical surgery, received adjuvant treatment, continuously monitored, being disease-free after five years of follow-up.