title: [Pattern recognition in the differential diagnosis of salivary lymphoepithelial lesions].
abstract: The prototype of a salivary lymphoepithelial lesion is the autoimmune disease Sjögren's syndrome with the characteristic lymphoepithelial duct lesions (LEL). The distinction of Sjögren's syndrome from cases with initial transformation into associated marginal zone B-cell lymphoma (MALT type) can be very challenging, whereby the presence of small "halos" can lead to over-diagnosis. The HIV-associated cystic lymphoepithelial lesion can be histologically almost identical to Sjögren's syndrome and often needs clinical correlation. The sporadic lymphoepithelial cyst of the parotid gland is a frequent finding and has no clinical consequence; however, this entity needs to be identified and distinguished from the above-mentioned entities. The most frequent diagnosis in resected submandibular glands is chronic-fibrosing sialadenitis, so-called Küttner's tumour. Altogether, there is a wide spectrum of lymphoepithelial interaction in the area of salivary glands, including biphasic lymphoepithelial tumours with an obligate lymphoid component, epithelial tumours with facultative tumour-associated lymphoid proliferation, and different processes of intraparotid lymph nodes. The immunohistological reaction for pan-keratin can be very helpful for a thorough pattern analysis of the different lymphoepithelial lesions. The relative frequency of the lesions in different salivary glands can also be diagnostically helpful.
authors.affiliation: Pathologisches Institut, Ludwig-Maximilians-Universität München, Thalkirchnerstr 36, 80337 München. Stephan.Ihrler@med.uni-muenchen.de
authors.forename: S
authors.initials: S
authors.lastname: Ihrler
authors.forename: P
authors.initials: P
authors.lastname: Adam
authors.forename: O
authors.initials: O
authors.lastname: Guntinas-Lichius
authors.forename: J D
authors.initials: JD
authors.lastname: Harrison
authors.forename: C
authors.initials: C
authors.lastname: Weiler
mesh_terms: D000235:Adenolymphoma / Q000175:diagnosis / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D002908:Chronic Disease; D003560:Cysts / Q000175:diagnosis / Q000473:pathology; D003937:Diagnosis, Differential; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis* / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D009367:Neoplasm Staging; D010306:Parotid Gland; D010307:Parotid Neoplasms / Q000175:diagnosis / Q000473:pathology; D010309:Parotitis / Q000175:diagnosis / Q000473:pathology; D012008:Recurrence; D012468:Salivary Gland Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D012469:Salivary Glands / Q000473:pathology; D012680:Sensitivity and Specificity; D012793:Sialadenitis / Q000175:diagnosis / Q000473:pathology; D012859:Sjogren's Syndrome / Q000175:diagnosis* / Q000473:pathology*; D013363:Submandibular Gland / Q000473:pathology; D014057:Tomography, X-Ray Computed