Coccoid Helicobacter pylori: An uncommon form of a common pathogen

Abstract

IntroduCtIonHelicobacter pylori is currently accepted as a major cause of gastritis and is implicated in the development of peptic ulcer disease, mucosa-associated lymphoid tissue lymphoma, and other cancers. Histological diagnosis is considered the gold standard as H. pylori can be frequently identified on standard hematoxylin and eosin staining. Histologically, Helicobacter species are most commonly recognized as seagull-shaped or curved, Gram-negative rods in the majority of cases; however, it has also been rarely encountered as corkscrew-shaped or even coccoid form. Because of the clinical implications associated with Helicobacter infections, it is critical to recognize the different morphological forms and identify the organisms to assure proper treatment of the infectious agent. Here, we describe a case of coccoid H. pylori. ClInICal rePortA 2-year-old immune-competent female child underwent upper endoscopy as a part of evaluation of suspected pancreatic insufficiency. Operative findings described normal-appearing esophagus, stomach, and duodenal mucosa. Microscopic examination of gastric mucosa biopsy showed small pieces of pyloric mucosa with focal areas of neutrophilic inflammation, rare gland abscesses, and small patches of lymphocytes and plasma cells in the lamina propria. Round, coccoid organisms were noted within gastric mucosal glands [Figure 1]. A recent history of antibiotic use was mentioned in the pathology report, with no further details given. The patient's complete medical records are not available for further review, and the pathology report and glass slides are the main sources available for us to review in preparation for this report. Discussion and commentsH. pylori are typically curved, Gram-negative bacilli which measure 3-5 μm in length and are frequently identified in the mucous of the stomach [Figure 2a]. [1] More recently, however, other variant forms such as Helicobacter heilmannii, a helical form, and an unusual coccoid form have also been identified in stomach biopsies [Figures 2b and 3].The coccoid form of H. pylori is speculated to represent a dormant or stressed form of the organism. It has been identified following failed antibiotic therapy or in other Microscopic recognition remains a major component of diagnosing specific infectious agents or, at the minimum, an important first step in initiating a workup to confirm a specific infectious etiology. However, organisms are known to adapt in response to treatment, not only by developing resistance mechanisms but also undergoing major morphologic changes in some cases. Such morphologic adaptation can make them drastically different and hence difficult to recognize or characterize by an unwary examiner. The purpose of this article is to highlight a rare and unusual form of Helicobacter pylori referred to as coccoid H. pylori.