engleski

INTRAOPERATIVE FROZEN SECTION ANALYSIS IN SURGICAL MANAGEMENT OF MAMMARY PHYLLODES TUMORS

INTRODUCTION: Phyllodes tumors (PT) are rare fibroepithelial lesions that account for less than 1% of all breast neoplasms. Although PT show many features of much commoner fibroadenomas (FA), they are likely to recur and can be locally aggressive. In addition, a small percent of PT show sarcomatoid features and have a potential to metastasize. Recurrence is directly related to incomplete resection without adequate margin of normal breast tissue. Because many of PT were preoperatively misinterpreted as FA, in many cases initial surgical excision is insufficient and re-excision is required. AIM: To evaluate the influence of intraoperative analysis on surgical management of PT. MATERIAL AND METHODS: Retrospective analysis included all PT diagnosed at University Hospital for Tumors during the 1995-2004 period. Patient age, tumor size, surgical method, number of examined frozen sections, and final histologic diagnosis were analyzed. RESULTS: During the 10-year period, a total of 77 female patients with the diagnosis of PT were recorded. The mean patient age was 44.5 (range 17-81) years, and the mean tumor size was 6.30 (range 1-24) cm. Fifty (65%) cases of PT were diagnosed as benign, 14 (18%) as borderline, and 13 (17%) as malignant. Primary surgical treatment involved lumpectomy in 48 (62%), wide surgical excision in 24 (31%), and mastectomy in the remaining 5 (7%) cases. Intraoperative analysis was performed in 64 (83%) cases. In most cases two frozen sections per biopsy were examined, varying from 1 to 4. Intraoperative diagnoses included PT in 50 (78%), FA in 12 (18%) and malignant mesenchymal tumor in 2 (3%) cases. All cases misinterpreted as FA were examined on just one frozen section. As a direct result of intraoperative diagnosis of PT, wide surgical excision was performed in 10 and simple mastectomy in 2 cases. DISCUSSION: Phyllodes tumor is a biphasic tumor composed of benign epithelial elements and a cellular spindle cell stroma. It accounts for approximately 2.5% of all fibroepithelial tumors of the breast. In most cases the pathological distinction from the much commoner FA is straight. Smaller lesions with nonspecific macroscopic features and recurrent tumors may present a diagnostic problem. Leaflike projections and hypercellular stroma suggest the diagnosis of PT. Other features common in PT include giant cells, foci of pseudoangiomatous stromal hyperplasia, patchy myxoid changes, cystic formations and metaplastic lesions. Most authors classify PT as benign, borderline and malignant. Grading is based on histologic evaluation of stromal cellularity, pleomorphism, mitotic activity, stromal overgrowth, and type of margins (pushing or infiltrative). This classification proved to be correlated with local breast recurrence in patients who did not undergo mastectomy. After lumpectomy or local excision, recurrence was observed in 21%, 46%, and 65% of patients with benign, borderline and malignant PT, respectively. Metastases occurred in less than 5% of borderline and as many as 25% of malignant PT. Most authors agree that complete excision with 1-2 cm of normal tissue around the tumor can prevent recurrences in benign PT, and significantly lowers the risk of recurrence in borderline PT. The high risk of recurrence and metastatic potential of malignant PT require radical approach and mastectomy is advised. CONCLUSION: Most histologic features of PT are recognizable on frozen sections. Triple preoperative assessment accompanied by intraoperative analysis helps separate rare PT from FA as well as benign from malignant PT. Adequate primary surgical management with wide excision lowers the risk of recurrence and need of secondary surgery in cases of benign and borderline PT, whereas simplemastectomy is reserved for larger lesions and malignant PT.

breast cancer; phyllodes tumor

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