Pergamon PII. S0964-1955 (96)00064-4 Oral Ontology Vol. 33, No. 3, pp. 204 208, 1997 1997 Elsevier Science Ltd. All rights reserved Printed in Great Britain 0964-1955197 $17.00+0.00 Immunohistochemical Study of Acinic Cell Carcinoma of Minor Salivary Gland M. M. Crivelini, 1 S. O. M. de Sousa 2 and V. C. de Arafijo 2 'Paulista State University, Araqatuba; and 2University of Silo Paulo, C. P. 8216, S.P., Brazil Acinic cell carcinoma (ACC) is a rare salivary gland tumour, making up 4% of all minor salivary gland turnouts. Typically, it is composed of acinic cells although transitional and duct-like cells are also identified. In the present study, a panel of antibodies was applied to eight minor salivary gland ACCs. Antibodies tested were: cytokeratins 7, 8, 13, 14, 18, 19, vimentin and actin (HHF35). Immu- nohistochemical staining revealed that cytokeratin 8, among the tested antibodies, was the more specific to neoplastic cells with a pattern of distribution quite variable and peculiar. This staining may be useful in the recognition of neoplastic acinic cells. ~ 1997 Elsevier Science Ltd Key words: salivary gland neoplasm, salivary gland-minor, salivary gland, immunohistochemistry Oral Oncology Vol. 33, No. 3, pp. 204-208, 1997 INTRODUCTION The acinic cell carcinoma (ACC) is a rare tumour of sali- vary glands occurring mainly in the parotid [1]. In minor salivary glands where the palatine glands are the main site of origin, it corresponds to 4% of all neoplasms, or 10% in the malignant group [2]. Typically, the tumour is composed of neoplastic acini-like cells, transitional cells and duct-like cells often arranged in a solid pattern. As to immunohistochemical markers for acinic cells in salivary gland tumours, only amylase has been widely stu- died [3-6]. However, some ACCs are negative to amylase [7, 8]. The purpose of this study was to determine the immuno- histochemical profile of minor salivary gland ACCs by applying a panel of antibodies. MATERIALS AND METHODS Eight minor salivary gland ACCs, retrieved from the files of the Oral Pathology Department of the University of $5o Paulo, School of Dentistry, Brazil, were studied. Haematoxylin-eosin stained sections were reviewed to con- firm the diagnosis. Formalin fixed tissue sections (3 /am) were used for immunohistochemical staining. Paraffin sections were treated, after deparaffinisation, three times for 5 min at 700W in citric acid (10mM, pH 6.0) in a micro- wave oven [9, 10], except for the reaction with CK19, when the sections were pre-digested with pronase. The antibodies Correspondence to V. C. de Arafijo. Received 31 May 1996; provisionally accepted 26 June 1996; revised manuscript received 3 Sep. 1996. used, their sources, concentrations, and times of incubation are listed in Table 1. After incubation with primary antibodies, sections were thoroughly washed and exposed to secondary antibodies. After further washing, they were exposed to a streptavidin- peroxidase complex. Diaminobenzidine was used as a chro- mogen, followed by 0.5% copper sulphate and finally coun- terstained with Mayer's haematoxylin. Positive controls for each CK, as indicated by the supplier, were used. Negative controls were incubated in buffer without primary anti- bodies. RESULTS Five of the eight ACCs were found in the palate glands, two in the buccal mucosa and one in the floor of the mouth. They occurred in 5 women and 3 men, with an average age of 35.5 years (Table 2). Table 1. Monoclonal antibodies used Incubation time (min)/ Antibodies Concentration temperature CK7* 1: 10 60 mirdroom temperature CK 8* 1:100 30 mirdroom temperature CK 13* 1:80 120 mirdroom temperature CK 14" 1:40 30 mirdroom temperature CK 18* 1:700 30 mirdroom temperature CK 19* 1:75 60 mirdroom temperature VIM~ 1:75 18 h/4°C HHF-35:~ 1:300 18 h/4~C *BioGenex Laboratories, San Ramon, California, U.S.A. tDako Corporation, Carpinteria, California, U.S.A. :~EnzoBiochemical,New York, U.S.A 204