Carcinoma ex benign pleomorphic adenoma of the parotid gland.

BACKGROUND: Carcinoma in pleomorphic salivary adenoma is a common histologic subtype of primary parotid malignancy. METHODS: In this study, 28 patients (predominantly male) with histologically diagnosed carcinoma in pleomorphic salivary adenoma presenting over 10 years were retrospectively reviewed. RESULTS: Only 25 percent of patients had a previously treated pleomorphic salivary adenoma. Although the presenting features suggested malignancy in some cases, overall they were nonspecific, overlapping with the presentation of benign disease. Preoperative investigations included fine needle aspiration cytology, which was only 29-percent sensitive, and computed tomography and/or magnetic resonance imaging. There were 14 superficial and 12 total or radical parotidectomies. The facial nerve was resected en bloc with the tumor in nine cases and immediately reconstructed with good reanimation results in patients with recent-onset facial paresis. Only 44 percent of patients had a complete histologic tumor clearance, and this was the most significant determinant of survival (p < 0.01, log-rank analysis). The locoregional control rate was 66 percent at 5 years, but recurrent disease proved invariably fatal. Five-year disease-specific survival was 44 percent with a high rate of disease-specific mortality (87 percent). CONCLUSIONS: Carcinoma in pleomorphic salivary adenoma is very difficult to diagnose preoperatively. Fine needle aspiration cytology had a disappointingly low sensitivity for this tumor, potentially misdirecting surgical management. While good locoregional disease control could be achieved with surgery and radiotherapy, carcinoma in pleomorphic salivary adenoma was shown to be aggressive with a high disease-specific rate of mortality. Given that incomplete tumor resection was the most important prognostic factor, a high index of clinical suspicion, radical ablative surgery, and immediate soft-tissue and nerve reconstruction for proven cases are advocated.

Iris melanocyte numbers in Asian, African American, and Caucasian irides.

PURPOSE: The anatomical basis for iris color has long been a controversial issue in ophthalmology. Recent studies demonstrated that in Caucasians, blue-eyed, gray-eyed, and hazel-eyed individuals have comparable numbers of iris melanocytes. The present investigation was carried out to compare melanocyte numbers in the irides of Asian, African American, and Caucasian brown-eyed individuals. METHODS: Paraffin-embedded sections from 71 brown-colored irides were incubated with rabbit anti-cow antibody against S100a, linked with an FITC conjugate antibody, and counterstained with Evans blue. Cells were counted under a fluorescence microscope and scored as melanocytes or other cells. Cell number, density, and iris area were calculated for each specimen. RESULTS: Caucasian and African American irides had comparable mean total melanocyte numbers. Asian irides had fewer total melanocytes than African American (P = .042) and Caucasian (P = .001) irides and smaller total number of cells (ie, melanocytes plus other cells) than African American (P = .054) or Caucasian (P = .009) irides. CONCLUSIONS: There is a statistically significant smaller mean total melanocyte number and mean total cellularity in Asian irides as compared to Caucasian and African American irides. This difference appears to be due to the combination of smaller iris area and lower melanocyte density in the Asian irides. The possibility exists that this may be a factor in ethnic variations in certain ocular diseases.