The aim of this study was to assess the correlation between technetium-99m methoxyisobutylisonitrile (MIBI) uptake by parathyroid adenomas, oxyphil cell content and volume of the lesions. Thirty-one patients with parathyroid adenomas were evaluated prospectively. Preoperative double-phase 99mTc-MIBI scintigraphy was performed in all patients and tracer uptake by parathyroid lesions was assessed semi-quantitatively employing region of interest ratios to normal adjacent neck areas. Surgical specimens underwent histological evaluation and oxyphil cell content was determined. The intensity of tracer uptake was compared with oxyphil cell content, volume of the lesions and serum levels of calcium and parathormone. 99mTc-MIBI tracer uptake was correlated with oxyphil cell content, volume of parathyroid lesions and the functional status of the parathyroid adenomas. Tracer accumulation in oxyphil cells might partially explain the preferential 99mTc-MIBI retention in parathyroid lesions.

Parathyroid hormone‐related protein (PTHrP) was first identified in human malignant tumors associated with humoral hypercalcemia of malignancy. We immunohisto‐chemically examined the distribution of PTHrP both in 7 normal parathyroid glands and in 20 parathyroid adenomas. Sixty five percent of parathyroid adenomas (13 cases) were positive for PTHrP, whereas only one normal parathyroid gland was positive for PTHrP in the area of transitional oxyphil cells. Many parathyroid adenomas (12 cases) were composed of both PTHrP positive cells and ‐negative cells, and these two different type of cells showed a tendency to form nodules respectively in parathyroid adenoma. Although both chief cells and oxyphil or transitional oxyphil cells were positive for PTHrP in parathyroid adenoma, oxyphil or transitional oxyphil cells were more responsible for PTHrP production than chief cells. Chief cells are thought to produce parathyroid hormone mainly in parathyroid adenoma. On the other hand, little is known concerning the function and role of oxyphil or transitional oxyphil cells. Our results suggest that oxyphil or transitional oxyphil cells in parathyroid adenoma may have some functional roles different from those of chief cells through the production of PTHrP.

Abstract THIS IS a rare benign tumor of the salivary glands described in the literature under different names: oncocytoma, adenoma, pyknocytoma, oxyphilic adenoma, acidophilic adenoma, oxyphilic cell adenoma, etc. The terminology is still more confused as evidenced in recent publications which consider histologically different tumors of the parotid gland to be identical and use their names interchangeably: papillary cystadenoma lymphomatosum or Warthin's tumor, adenolymphoma, oxyphilic granular-cell tumors and benign lymphoepithelial lesions or Mikulicz's disease, this due to the fact that these lesions contain oncocytes in different amounts.1 The oxyphilic granular-cell adenoma is a tumor formed by cells called oncocytes, this designation used for the first time by Hamperl2 who derived it from the Greek word Ογκονζ θαι meaning "increase in bulk." He credits Schaffer with first describing these cells as "granular swollen cells," and later Zimmerman called them pyknocytes. It is considered that the first such tumor described in References 1. Eneroth, C.M.: Oncocytoma of the Major Salivary Glands , J Laryng 79:1064-1072, 1965.Crossref 2. Hamperl, H.: Beiträge Zur normalen und pathologischen Histologie menschlicher Speicheldrüsen , Z Mikr Anat Forsch 27:1-55, 1931. 3. Duplay, M.: Adénome de la glande sousmaxillaire , Arch Gén Med 1:601-603, 1875. 4. Christopherson, W.M.: Oncocytoma of the Parotid Gland , Arch Path 48:96-98, 1949. 5. Foote, F.W., Jr., and Frazell, E.L.: Tumors of the Major Salivary Glands , Cancer 6:1065-1133, 1953.Crossref 6. Trier, J.S.: Fine Structure of Parathyroid Gland , J Biophys Biochem 4:13-22, 1958.Crossref 7. Hamperl, H.: Z Krebsforsch 64:127, 1962 8. (cited by Eneroth, C.M.).1 9. Meza-Chávez, L.: Oxyphilic Granular-Cell Adenoma of the Parotid Gland (Oncocytoma): Report of Five Cases and Study of Oxyphilic Granular-Cell (Oncocytes) in Normal Parotid Glands , Amer J Path 25:523-538, 1949. 10. Bauer, W.H., and Bauer, J.D.: Classification of Glandular Tumors of Salivary Glands: Study of 143 Cases , Arch Path 55:328-346, 1953. 11. Hamperl, H.: Benign and Malignant Oncocytoma , Cancer 15:1019-1027, 1962.Crossref

Oxyphil-cell adenoma (oncocytoma) is a benign tumor made up of acidophilic cells usually referred to as oncocytes. The tumor is always encapsulated, usually rounded or ovoid, but may appear irregular or coarsely nodular. There have been no instances of multiple separate or discrete tumors within the same gland. The tumors are homogeneous or lobulated and are soft and resilient. The cut surface may be brownish red, brownish pink, or pale pink. Cystic areas have been seen, but unlike those in papillary cystadenoma lymphomatosum, they are not an important characteristic. They are usually 3 to 4 cm. in diameter. Microscopically, the cells are large, with pink cytoplasm and small, rounded nuclei. Cell outlines are distinct. The cytoplasm is finely granular under high power. Mitoses are usually absent, but, if they are present, they are few in number. The cells are characteristically arranged in columns or cords a few cells thick and

Oncocytomas of the salivary gland are uncommon neoplasms that are characterized by polygonal cells with abundant granular eosinophilic cytoplasm and relatively uniform nuclei. They are benign in nature and have a low recurrence rate with complete surgical excision. Though uncommon, oncocytic and clear cell variants of malignant tumors may histologically mimic oncocytomas and identification of their distinguishing features is essential. A classic example of an oncocytoma is discussed.

Abstract • A well-differentiated, oncocytic adenocarcinoma of the lacrimal sac recurred locally in a patient during a period of 13 years. This appears to be the second documented instance of such a neoplasm. References 1. Schenck NL, Ogura JH, Pratt LL: Cancer of the lacrimal sac: Presentation of five cases and review of the literature . Ann Otol Rhinol Laryngol 82:153-161, 1973. 2. Ryan SJ, Font FL: Primary epithelial neoplasms of the lacrimal sac . Am J Ophthalmol 76:73-88, 1973. 3. Aurora AL: Oncocytic metaplasia in a lacrimal sac papilloma . Am J Ophthalmol 75:466-468, 1973. 4. Ostrachowicz M, Meyer J: A case of oncocytic adenoma (oxyphilic granulocellular adenoma) of the lacrimal sac . Klin Oczna 33:197-202, 1963. 5. Biggs SL, Font RL: Oncocytic lesions of the caruncle and other ocular adnexae . Arch Ophthalmol 95:474-478, 1977.Crossref 6. Hamperl H: Onkocyten und onkocytome . Virchows Arch Pathol Anat 335:452-483, 1962.Crossref 7. Noguch TT, Lonser ER: Oncocytoma (oxyphil-cell adenoma) of the caruncle of the eyelid . Arch Pathol 69:516-518, 1960. 8. Radnot M, Lapis K: Ultrastructure of the caruncular oncocytoma . Ophthalmologica 161:63-77, 1970.Crossref 9. Deutsch AR, Duckworth JK: Oncocytoma (oxyphilic adenoma) of the caruncle . Am J Ophthalmol 64:458-461, 1967.