Introduction/Background Invasive pleomorphic lobular carcinoma(PLC) represents 15% of invasive lobular carcinoma(ILC) and is thought to be more agressive with a worse prognosis.

Methodology We retrospectively reviewed the clinical records of 18 patients diagnosed with PLC in Salah Azaiez Institute (2006–2021)

Results All reported cases were females, with a median age of 59.5.

Median tumor size was 30mm. Four patients had multifocal lesions while only two presented with bilateral tumors.

Only 5 cases were classified as stage T3/4 tumors and two patients were metastatic at the time of diagnosis

65% of the patients had preoperative core needle biopsy yielding a diagnosis of PLC in only 6 cases(46.15%). Two patients did not undergo surgery owing to the advanced stage at presentation and chemotherapy was conducted instead.

Among patients for whom surgery was stated, 11 patients underwent total mastectomy(64.7%). Sentinel lymph node dissection was performed on exactly 4 patients .Lymph nodes were free of tumor in the majority of cases.

On pathological examination, LPC was associated with invasive ductal carcinoma in 9 cases.

Almost 90% of the cases were high-grade carcinomas with a lympho-vascular invasion present in 8 cases. The tumor cells were positive for hormone receptors in 90% of cases while HER2neu was negative in 94.44% of cases.

Data on adjuvant treatment was available on merely 12 patients. Concomitant radio-chemotherapy with endocrine therapy was indicated for 10 patients, while others received either exclusive radiotherapy or chemotherapy.

The median follow-up was 27 months .At that time, most of the patients were free of disease, while one patient developed ipsilateral relapse for which she underwent total mastectomy . Two patients died 04 months after the onset of the treatment.

Conclusion The PLC’s treatment approach is not well established however surgical resection remains the standard-of-care. More studies are required for further understanding of its clinical behavior and optimal treatment guidelines.

Disclosures the authors have nothing to disclose.