[Diffuse hyperplastic oncocytosis of the parotid gland]. / Die diffuse Onkozytose der Glandula Parotidea.

BACKGROUND: Oncocytes are epithelial cells characterized by an granular, eosinophilic cytoplasma, and a centrally situated, pycnotic nucleus. These cells were first observed by Hamperl 1931 in the salivary glands. Ultrastructural studies have shown that the cytoplasma of these cells is filled with numerous large and bizarre mitochondria. The exact biological significance of oncocytes is unknown - Becker, Donath and Seifert suggest an intracellular metabolic disturbance associated with mitochondriopathy, caused by an age dependent metabolic defect. Oncocytes are not specific for the salivary glands; they are also found in the thyroid gland, parathyroid gland, liver, pancreas, esophagus and the kidney. Solitary oncocytes appear most often as incidental findings in aging salivary tissue, they are present in persons older than 70 years up to 80 %. The diffuse hyperplastic oncocytosis of the parotid gland represents an extremely rare, non-tumorous alteration of the parotid gland. Caused by an extensive metaplasia of acinic and ductal cells nearly the entire gland consists of oncocytes. Clinically it is characterized by swelling of the parotid gland. Oncocytic adenomatous hyperplasia is a different disease. It represents a multifocal oncocytic proliferation of the duct system. In contrast to diffuse oncocytosis remnants of the original salivary tissue with acini and fatty tissue are usually present between the oncocytic nodules. Typical oncocytomas may possibly develop from such oncocytic proliferation by a tendency to confluent growth. METHODS: Cases of diffuse hyperplastic oncocytosis of the parotid gland were identified by literature review. RESULTS: Worldwide diffuse hyperplastic oncocytosis of the parotid gland has been observed in 8 cases (Fig. ) as of today. PATIENT: We report and discuss the case of a 78-year-old male, who was refered to our hospital because of a painless mass of the left parotid gland. MRI showed a tumorous lesion with a diameter of about 5 cm. Lateral parotidectomy was performed. Histology revealed an extremely rare case of diffuse hyperplastic oncocytosis. There has been no recurrence of tumor after 2 years. CONCLUSIONS: Diffuse hyperplastic oncocytosis of the parotid gland is an extremely rare benign disorder, complete excision of the tumor-like lesion is curative. In literature there has been no report of recurrence, malignant transformation or metastasizing illness.

Combination of surgery and gamma knife radiosurgery--a therapeutic option for patients with tumors of nasal cavity or paranasal sinuses infiltrating the skull base.

UNLABELLED: The purpose of this study was to investigate whether patients operated for skull base-infiltrating malignant tumors of the nasal cavity and/or the paranasal sinuses benefit from an additional Gamma knife radiosurgery. CASE SERIES: eight consecutive patients, (male: female ratio = 1:1, mean age = 52 years, range 34 to 79 years) presented with 2 cyclindric cell carcinomas, 2 adenocarcinomas, 2 malignant neuroblastomas, 1 squamous cell carcinoma, 1 amelanotic melanoma. Tumor stages (UICC) were: 1 T1, 3 T2, 3 T3, 1 T4, all N0, all M0. All patients were primarily treated surgically and 4 weeks later received additional stereotactic radiosurgery. Follow-up was based on computerized tomography (CT), magnetic resonance imaging (MRI), endoscopy, and biopsy. The course of disease was compared to tumor courses with surgery but without radiosurgery reported in literature. Four times endoscopic endonasal surgery (EES), once EES in combination with fluorescein technique, once EES plus external approach of frontal sinus, once lateral rhinotomy was performed. All 8 cases underwent radiosurgery (Leksell gamma knife) 4 weeks after surgery. Thirty six months after radiosurgery 6 patients were alive (4 patients without evidence of disease, 1 patient with pulmonary metastasis but without local recurrence, 1 patient with regional metastasis but no local recurrence), 1 patient died 11 months after treatment due to disease, 1 patient died due to a second malignancy. No negative or adverse effects due to radiosurgery were observed. The combination of microsurgery with Leksell Gamma knife radiosurgery appears to be an encouraging therapeutic option. To date no adverse effects have been observed in the presented cases.