title: Obligate basal cell component in salivary oncocytoma facilitates distinction from acinic cell carcinoma.
abstract: The differential diagnosis between benign salivary oncocytoma (ONC) and low-grade malignant acinic cell carcinoma (ACC) can be difficult due to a significant histomorphological overlap of the structural and cytological presentation of both tumor types. To the best of our knowledge a comprehensive study comparing (immuno-)histological markers in cases of difficult differential diagnosis between ONC and ACC has not yet been performed. We investigated a panel of different immunohistochemical (CK5/6, CK14, CK7, CK18, p63 and Ki67) and histochemical (PAS, alpha-amylase) markers in 12 cases of ONC and 19 cases of ACC. The statistically significant stronger expression of CK7 in ONC and stronger expression of PAS and alpha-amylase in ACC in routine practice each is hampered by a pronounced overlap between both tumor groups. The obligate presence of an additional small basal cell component in all cases of ONC, demonstrable with p63 and CK5/6, enables a straightforward distinction from ACC, being constantly devoid of a basal cell component. Unexpectedly, CK14 is not a suitable marker for a reliable proof of these basal cells. The detection of this basal cell component in ONC in routine Hematoxylin-eosin stain is difficult and in some cases not possible; therefore, immunohistochemistry with p63 or CK5/6 is recommended for selected cases.
authors: Institute of Pathology, Ludwig Maximilian University, Munich, Germany. christoph.weiler@med.uni-muenchen.de
authors: Christoph
authors: C
authors: Weiler
authors: Simone
authors: S
authors: Reu
authors: Pamela
authors: P
authors: Zengel
authors: Thomas
authors: T
authors: Kirchner
authors: Stephan
authors: S
authors: Ihrler
mesh_terms: D018249:Adenoma, Oxyphilic / Q000737:chemistry / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D018267:Carcinoma, Acinar Cell / Q000737:chemistry / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053555:Keratin-5 / Q000032:analysis; D053553:Keratin-6 / Q000032:analysis; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012468:Salivary Gland Neoplasms / Q000737:chemistry / Q000473:pathology*; D015534:Trans-Activators / Q000032:analysis; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; C503940:KRT5 protein, human; D053555:Keratin-5; D053553:Keratin-6; C115051:TP63 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins