title: Multifocal adenomatous oncocytic hyperplasia of the parotid gland.
abstract: Multifocal adenomatous oncocytic hyperplasia (MAOH) is a non-neoplastic lesion that is classified as oncocytosis. MAOH is a rare entity of the parotid gland and accounts for approximately 0.1% of salivary gland lesions. Here, we report a case of MAOH of the parotid gland. The patient was a 71-year-old woman who presented with discomfort at the left side of her neck. Fine-needle aspiration cytology of the parotid gland revealed a loose sheet-like cluster of round to polygonal cells with granular cytoplasm against a hemorrhagic background. The cells had round to oval, centrally located nuclei with granular chromatin and without distinct nucleoli. Histologically, the lesion was formed of many variable-sized nodules, comprising oncocyte-like cells with small round nuclei and eosinophilic granular cytoplasm that was positive for mitochondrial antibodies. The diagnosis of MAOH is difficult to make by cytology alone, because the findings overlap with those of other oncocytic lesions. In particular, the cytological findings of MAOH have not been sufficiently reported to date. A correlation of cytology and histology was expected.
authors.affiliation: Department of Pathology II, Kansai Medical University, Hirakata, Japan ; Division of Diagnostic Cytopathology and Histopathology, Kansai Medical University Takii Hospital, Moriguchi, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kinoshita
authors.affiliation: Division of Surgical Pathology, Seichoukai Fuchu Hospital, Izumi, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Harada
authors.affiliation: Cancer Education and Research Center, Osaka University Graduate School of Medicine and Health Science, Osaka, Japan.
authors.forename: Tadao K
authors.initials: TK
authors.lastname: Kobayashi
authors.affiliation: Department of Pathology II, Kansai Medical University, Hirakata, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Yoshizawa
authors.affiliation: Department of Pathology II, Kansai Medical University, Hirakata, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yuri
authors.affiliation: Division of Surgical Pathology, Hyogo Prefectural Amagasaki Hospital, Amagasaki, Japan.
authors.forename: Kosho
authors.initials: K
authors.lastname: Takasu
authors.affiliation: Department of Pathology II, Kansai Medical University, Hirakata, Japan.
authors.forename: Airo
authors.initials: A
authors.lastname: Tsubura
authors.affiliation: Division of Diagnostic Cytopathology and Histopathology, Kansai Medical University Takii Hospital, Moriguchi, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Shikata
keywords: Cytology; Histology; Multifocal adenomatous oncocytic hyperplasia; Oncocytes; Parotid gland