Is pleomorphic lobular carcinoma really a distinct clinical entity?

Area of Science:

• Oncology
• Pathology
• Surgical Breast Disease

Background:

• Pleomorphic lobular carcinoma (PLC) clinical behavior and management strategies are not well-defined due to limited case series.
• This study compares the clinical and pathological characteristics of PLC to classic invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC).

Purpose of the Study:

• To define the clinical behavior of pleomorphic lobular carcinoma (PLC).
• To compare PLC to classic ILC and invasive ductal carcinoma (IDC).
• To inform clinical management strategies for PLC.

Main Methods:

• Retrospective review of clinical and histopathologic data from 5,635 breast cancer patients (9/1996-5/2003).
• Pathologic re-review of 356 ILC cases identified 52 PLC, 298 classic ILC, and 6 IDC.
• Comparison of clinical, pathologic, and treatment factors using Wilcoxon rank sum and Fisher's exact tests.

Main Results:

• Pleomorphic lobular carcinoma (PLC) tumors were larger (20mm vs. 15mm vs. 13mm) and had more positive lymph nodes (median 1 vs. 0 vs. 0) compared to ILC and IDC.
• Mastectomy was more frequent for PLC (63.5%) than ILC (38.7%) or IDC (28.8%).
• Metastatic disease occurred more frequently in PLC patients (11.5%) than ILC patients (3.7%).

Conclusions:

• Pleomorphic lobular carcinoma (PLC) is a distinct clinical entity.
• PLC presents at a more advanced stage than classic ILC or IDC.
• PLC may necessitate more aggressive surgical and adjuvant treatment approaches.