Clinicopathologic Characteristics and Prognostic Factors of Primary and Recurrent Pleomorphic Adenoma: A Single Institution Retrospective Study of 705 Cases.
| Publication Type | Academic Article |
| Authors | Alzumaili B, Xu B, Saliba M, Abuhashem A, Ganly I, Ghossein R, Katabi N |
| Journal | Am J Surg Pathol |
| Volume | 46 |
| Issue | 6 |
| Pagination | 854-862 |
| Date Published | 11/15/2021 |
| ISSN | 1532-0979 |
| Keywords | Adenoma, Pleomorphic, Carcinoma, Squamous Cell |
| Abstract | Although pleomorphic adenoma (PA) is benign, it may recur and prompt further treatment with radiotherapy (RT). This study investigated the prognostic features of primary and recurrent PAs. A total of 705 PAs (613 primary and 92 recurrent) were analyzed. The following parameters: age, site and size, status of resection, histologic features, and clinical management were documented and correlated with recurrence-free survival. For primary PAs: The mean patient age was 50 years (female/male: 2/1), the median size was 2.1 cm (range: 0.5 to 9.0 cm), and the most common location was the parotid (92%). Tumors showed the following: complete encapsulation (25%), involvement of the surrounding salivary gland/fat (74%), hypercellularity (26%), ≥10 pseudopods (15%), squamous metaplasia (43%), mitoses (49%), intravascular tumor deposit (n=1), close proximity to nerves (n=2), positive margin (15%), and suboptimal resection (2%). The recurrence rate was 3.4% and malignant transformation was <1%. On univariate analysis, age below 30, mitosis ≥3/10 HPFs, squamous metaplasia, hypercellularity, and suboptimal resection correlated with recurrence-free survival. On multivariate analysis, only age below 30, mitosis ≥3/10 HPF and suboptimal resection predicted recurrence. For recurrent PAs: The resected primary PAs were fragmented in 58%. Forty-eight percent of patients had subsequent recurrences, mostly within 10 years, and 1 patient developed a subsequent malignant transformation. Forty-two percent of patients received RT. On univariate analysis, only RT was associated with better outcome (P=0.033). Young age, high mitoses, and specimen integrity predicted recurrence in primary PA. Recurrent PAs are difficult to eradicate, and 48% of these recurred for the second time, mostly within 10 years. |
| DOI | 10.1097/PAS.0000000000001837 |
| PubMed ID | 34772841 |
| PubMed Central ID | PMC9106806 |