Oral pyogenic granuloma (PG) is generally a solitary benign connective tissue proliferation of unknown etiology. It is the most common type of oral inflammatory hyperplasia histologically characterized by proliferation of granulation tissue with inflammatory infiltrates and high angiogenic capacity. Vascular neoformations of different diameters are usually present. Due to their structural characteristics, tendency to bleed, and rapid and alarming growth rate, these neoformations may have serious consequences. Sometimes, it is complex to make an accurate diagnosis. Therefore, adequate management and treatment are based on the characteristics and systemic conditions of each patient. This review was carried out to provide an overview of the factors involved in, or attributed to the etiopathogenesis of oral PG. It describes the different forms of presentation and clinical evolution, as well as the most frequent signs and symptoms that characterize this disease, while incorporating recent radiographic and microscopic findings. In addition, it describes the different modalities for the management of oral pyogenic granuloma depending on the particular characteristics of each patient.

Hyperplastic nodules (HNs) are benign polypoid lesions of the colorectal mucosa reportedly caused by hyperplasia of the crypt epithelial cells. They differ from hyperplastic polyps because the crypts do not have histologically serrated changes. HNs often occur in the rectal mucosa and tend to be multifocal. We have proposed a new colitis nucleomigrans (CN) concept as the third type of microscopic colitis. Our histopathological criteria of CN include: i) chained nuclear migration to the middle part of the surface-lining columnar epithelium, ii) apoptotic nuclear debris scattered in the eosinophilic cytoplasm underneath the nuclei, and iii) mild to moderate chronic inflammation in the lamina propria. Immunostaining for cleaved-caspase 3 revealed apoptotic bodies. In this study, we report that most HN lesions share the histological features with CN, representing polypoid CN. We evaluated 108 lesions of HN in total, and 94 (87%) were reclassified as polypoid CN. In the polypoid CN, the lamina propria mucosae were uniformly edematous, suggesting that accelerated apoptosis of the mucosal surface epithelium may cause osmotic dysregulation to form localized mucosal elevations.

Hyperplastic dental follicles (HDFs) represent odontogenic hamartomatous lesions originating from pericoronal tissues and are often associated with impacted or embedded teeth. These lesions may occasionally feature unique calcifying bodies, known as calcifying whorled nodules (CWN), characterized by stromal cells arranged in a whorled or spiral fashion. CWNs are typically observed in multiple calcifying hyperplastic dental follicles or regional odontodysplasia. In our study, we examined 40 cases of HDFs, including nine instances with characteristics of CWNs, which were infrequently accompanied by odontodysplasia. Histological examination was conducted on all 40 cases, with immunohistochemical analysis performed on 21 of them. Among the cases with CWN, nine affected a single embedded tooth, with one exception. CWNs exhibited diverse calcifications featuring sparse or entirely deposited psammoma bodies, and some displayed dentinoid formation. Immunohistochemically, stromal cells of HDFs were frequently positive for CD56 and nestin. In contrast, CWNs were negative for CD56 but positive for nestin and HES1, with a few DSP-positive calcified bodies. Our results revealed that hamartomatous calcifying HFDs can impact multiple and single-embedded teeth. CWNs composed of nestin and HES1-positive ectomesenchymal cells demonstrated the potential to differentiate into odontoblasts and contribute to dentin matrix formation under the influence of HES1. This study is the first report documenting odontoblastic differentiation in HDFs.

Objectives: We aimed to clarify the endoscopic and clinicopathological features of raspberry-shaped gastric lesions (RSGLs) and to establish an endoscopic diagnostic algorithm for RSGLs. Methods: We collected RSGLs from an endoscopic database at our hospital between May 2009 and August 2021. All RSGLs were histopathologically classified and compared based on their endoscopic and clinicopathological characteristics. Results: Sixty-five RSGLs in 54 patients were classified into five histopathological types: gastric adenocarcinoma of foveolar type (GA-FV, n = 43), gastric adenocarcinoma of fundic-gland type (GA-FG, n = 2), gastric adenocarcinoma of fundic-gland mucosa type (GA-FGM, n = 4), hyperplastic polyp (HP, n = 12), and proton pump inhibitor-related lesion (PPI-L, n = 4). All RSGLs exhibited polygonal or curved marginal crypt epithelium (MCE). GA-FV lesions had homogenously reddish (95%) and irregular microvascular (MV) pattern (91%). GA-FG lesions were heterogeneously reddish with a submucosal tumor shape (100%) and had a regular MV pattern (50%). GA-FGM lesions were homogenously reddish (75%) and occasionally had a submucosal tumor shape (50%) with an irregular MV pattern (75%). HP and PPI-L were homogeneously reddish (93%), with linear or dotted MCE (81%) and a regular MV pattern (100%). Conclusion: Our diagnostic algorithm for RSGLs constructed using endoscopic features might be useful for the endoscopic differential diagnosis of RSGLs.