International Medical Case Reports Journal (Jun 2021)
Pancreatic Intraductal Papillary Mucinous Neoplasm with Hyaline Globules (Thanatosomes): Report of Two Cases
Abstract
Mitsuhiro Tachibana,1 Ryohei Koreyasu,2 Kazuyasu Kamimura,2 Yutaka Tsutsumi1,3 1Department of Diagnostic Pathology, Shimada City General Medical Center, Shimada, Shizuoka, Japan; 2Department of Surgery, Shimada City General Medical Center, Shimada, Shizuoka, Japan; 3Diagnostic Pathology Clinic, Pathos Tsutsumi, Inazawa, Aichi, JapanCorrespondence: Mitsuhiro TachibanaDepartment of Diagnostic Pathology, Shimada City General Medical Center, Noda 1200-5, Shimada, Shizuoka, 427-8502, JapanTel +81-547-35-2111 (ext. 2273)Fax +81-547-35-2182Email [email protected]: Hyaline globules (HGs; thanatosomes) represent a morphologic entity representing a metabolic imbalance common to all cell types. HGs, intracytoplasmic eosinophilic globular accumulations of proteinaceous material of varying sizes, have been observed in varied tumors and benign tissues. Different explanations have been proposed for their formation, according to the tumor type and anatomic location. An earlier study suggested that HGs were closely related to apoptosis. There are some reports describing HGs in pancreatic neoplasms, such as intraductal oncocytic papillary neoplasm, solid-pseudopapillary neoplasm, oncocytic endocrine neoplasm, and invasive ductal adenocarcinoma; however, this is the first report describing HGs in pancreatic intraductal papillary mucinous neoplasm (IPMN). An ultrastructural study was performed to visualize HGs in two pancreatic IPMNs of gastric type (one non-invasive malignancy and another adenoma). Light microscopically, intracytoplasmic HGs were clustered multifocally. HGs were periodic acid-Schiff-positive and diastase-resistant, and fuchsinophilic with Masson’s trichrome stain. The diameter ranged from 4.7 to 20.6 μm (mean: 13.3, median: 14.1). They were mainly seen at the supranuclear position and occasionally with subnuclear location. Ultrastructurally, HGs were round in shape and homogenously electron-dense without mitochondria or chromatin-like condensation. The nuclei of HGs-containing mucous columnar cells appeared intact without evidence of apoptosis. It is worth emphasizing that HGs in the pancreatic IPMN of gastric type belong not to apoptotic bodies but to proteinaceous secretory materials.Keywords: pancreas, pancreatic intraductal papillary mucinous neoplasm, hyaline globules, thanatosomes
