Chronic anisakiasis presenting as a mesenteric mass

First Case of Human Anisakiosis in Greece: Acute Invasive Infection Mimicking Peritoneal Malignancy

Consumption of raw and mildly processed seafood, in the context of modern Western world eating trends, is recognized as a major driver for human fish-borne infections. However, these zoonoses and their unfamiliar risks remain neglected and underappreciated among European diagnosticians. In contemporary Europe anisakidosis is one of the most important fish-borne zoonoses. It is caused by ingesting the third-stage infective larvae of the nematode parasites that belong to the family Anisakidae. The case described herein, is an intestinal and ectopic form of anisakiosis (Anisakis spp.), causing symptoms of subacute abdomen and masquerading as an intraperitoneal malignancy. It is the first anisakidosis case reported in Greece, affecting a young patient who had been repeatedly exposed to the parasite by consuming homemade raw fish. Right hemicolectomy, omentectomy and excision of a descending colon nodule were uneventfully performed. The pathology report confirmed granulomatous tissue with eosinophilic infiltration and parasites that were morphologically and molecularly identified as Anisakis spp. Although challenging, acquiring an accurate diagnosis of anisakidosis can prevent unnecessary surgery, as the infection typically is self-resolving, and if treatment is deemed necessary, it can be limited to antiparasitic medication. However, in rare cases, extra-gastrointestinal migration of larvae can cause severe damage with practically unknown risks, posing a diagnostic and therapeutic dilemma. In such a clinical case scenario, surgical exploration can decisively contribute to a definitive diagnosis and early identification of intraabdominal complications necessitating surgical intervention.

[Infectious Gastric Diseases Other than Helicobacter]

In addition to Helicobacter pylori, the acute bacterial causes of infectious gastritis, include phlegmonous gastritis, gastric tuberculosis, and gastric syphilis. Bacterial gastritis often improves with appropriate broad-spectrum antibiotics, emphasizing the need for prompt diagnosis and treatment based on the clinical and endoscopic findings. Among viral gastritis, cytomegalovirus gastritis, primarily occurring in immunocompromised patients, necessitates antiviral intervention, while immunocompetent individuals typically achieve amelioration by administering proton pump inhibitors. In contrast, most gastric infections caused by the Epstein-Barr virus (EBV) are asymptomatic, but an EBV infection is a cause of stomach cancer. EBV-associated gastric cancer exhibits distinct clinical, pathological, genetic, and post-genetic mutation features, making it clinically significant. The colonization of Candida albicans in the stomach is uncommon, and typical antifungal treatment is unnecessary. Candida infections in gastric ulcers can be treated with anti-ulcer treatment alone. Lastly, anisakidosis in the stomach, which occurs when consuming raw seafood, can manifest in various clinical presentations and is typically treated through endoscopic removal of the nematode. This article aims to contribute to the rapid diagnosis and treatment of rare stomach infections beyond Helicobacter pylori in real clinical situations.

Anisakiasis: Imaging findings

OBJECTIVE

To review the main findings for anisakiasis in the different imaging tests that can be used to diagnose it, based on studies done at our center.

CONCLUSION

The presence of Anisakis species in food consumed in Western countries is becoming more common. Patients with anisakiasis present with acute abdomen; there are no specific clinical signs or laboratory findings. Careful history taking is key to discovering exposure to Anisakis-contaminated food, but this task is hindered by unfamiliarity with the condition and lack of suspicion and is also confounded by the variable latency period after ingestion of Anisakis-contaminated food. Give the nonspecific presentation, patients with anisakiasis often undergo imaging tests to rule out other processes. Thus, radiologists need to be familiar with the spectrum of imaging findings that should lead to the inclusion of anisakiasis in the differential diagnosis, so they can guide clinicians toward directed history taking and specific tests.

Endosonographic Findings and the Natural Course of Chronic Gastric Anisakiasis: A Single-Center Experience

BACKGROUND

Chronic gastric anisakiasis is a rare, usually asymptomatic, and difficult to diagnose infection incidentally discovered during endoscopy, resembling a subepithelial tumor (SET). Because its endoscopic ultrasonography (EUS) findings are not established, it is occasionally misdiagnosed as gastrointestinal mesenchymal tumors and removed by endoscopic or surgical resection. We aimed to assess the characteristic EUS findings of chronic gastric anisakiasis and the clinical course during follow-up.

METHODS

The database of all patients who underwent EUS at Pusan National University Hospital (Busan, Korea) between January 2011 and December 2016 was retrospectively analyzed. A total of 28 SET cases with EUS features suggesting chronic gastric anisakiasis were included in the study. The EUS, histopathologic, and follow-up endoscopic features were analyzed.

RESULTS

On EUS, the lesions were mainly located in the submucosal and/or propria muscle layers. Twenty-seven lesions (27/28, 96%) showed hypoechoic echogenicity, and 22 lesions (22/28, 79%) were heterogeneous. Hyperechoic tubular structures suggesting denaturalized Anisakidae larvae were seen in 22 lesions (22/28, 79%). Endoscopic biopsies revealed significant eosinophil infiltration (≥30 per high-power field) in 12 lesions (12/21, 57%). During the median follow-up period of 9 months (range, 1-55 months), SETs decreased or subsided in 26 lesions (26/28, 93%) with no change in the size of the two lesions (2/28, 7%).

CONCLUSIONS

Chronic gastric anisakiasis, although rare, should be included in the differential diagnoses for gastric SETs, especially in regions where raw fish is widely consumed. EUS findings suggesting chronic gastric anisakiasis are heterogeneously hypoechoic lesions with hyperechoic tubular structures, mainly in the submucosal and/or muscularis propria layers. Because chronic gastric anisakiasis decreases or subsides in most cases, follow-up endoscopy 6-12 months later is recommended.

A Case of Ectopic Peritoneal Paragonimiasis Mimicking Diverticulitis or Abdominal Abscess

Paragonimiasis is a parasitic disease caused by Paragnonimus species. The primary site of infection is the lung, and extrapulmonary involvement is also reported. When infected with Paragonimus westermani, which is the dominant species in Korea, the central nervous system is frequently involved along with the liver, intestine, peritoneal cavity, retroperitoneum, and abdominal wall. Ectopic paragonimiasis raises diagnostic challenge since it is uncommon and may be confused with malignancy or other inflammatory diseases. Here, we report an ectopic paragonimiasis case initially presented with recurrent abdominal pain. The patient developed abdominal pain 3 times for the previous 3 years and the computed tomography (CT) of the abdomen revealed fluid collection with wall enhancement. Recurrent diverticulitis was initially suspected and part of the ascending colon was resected. However, the specimen showed intact colon wall without evidence of diverticulitis and multiple parasite eggs and granulomas were found instead. The size of about 70 μm, the presence of an operculum and relatively thick egg shell suggested eggs of Paragonimus species. With appropriate exposure history and a positive antibody test, the definitive diagnosis was made as peritoneal paragonimiasis.

Asymptomatic anisakiasis of the colon incidentally diagnosed and treated during colonoscopy by retroflexion in the ascending colon

A 74-year-old man with diabetes underwent colonoscopy as routine screening for colon cancer. An Anisakis larva was found incidentally during colonoscopy using the retroflexion technique in the ascending colon, and was removed using a forceps. Asymptomatic colonic anisakiasis is very rare, and few reports have described diagnosis and treatment of anisakiasis during colonoscopy by the retroflexion technique in the ascending colon. We have reported this rare case along with a literature review.

Helminthosis and eosinophilia in Spain (1990-2015)

The finding of blood eosinophilia in a patient is a relatively frequent reason to refer him/her to a Clinical Department of Infectious Diseases. The doctor usually intends to rule out a parasitic disease in the autochthonous population, travelers or immigrants. It is uncommon for an eosinophilia to be produced by protozoa infection, whereas helminth parasites are more frequently associated with an increase of eosinophil counts in the infected patient. Eosinophilia can be the only abnormal finding, or it could be part of more complex clinical manifestations suffered by the patient. Furthermore, many, but not all, helminth infections are associated with eosinophilia, and the eosinophil level (low, high) differs according to parasite stages, helminth species, and worm co-infections. The purpose of the present article is to carry out a systematic review of cases and case series on helminth infections and eosinophilia reported in Spain from 1990 to 2015, making a distinction between autochthonous and imported (immigrants and travelers) cases, and studying their relationship with immunodepression situations.

Acute Small-Bowel Obstruction From Intestinal Anisakiasis After the Ingestion of Raw Clams; Documenting a New Method of Marine-to-Human Parasitic Transmission

Enteric anisakiasis is a known parasitic infection. To date, human infection has been reported as resulting from the inadvertent ingestion of the anisakis larvae when eating raw/undercooked fish, squid, or eel. We present a first reported case of intestinal obstruction caused by anisakiasis, after the ingestion of raw clams.

Parametrial anisakidosis

Anisakidosis is a parasitic infection caused by anisakid nematodes in the genera Anisakis and Pseudoterranova. Infection is not uncommon in the United States due to increased raw seafood consumption. We report the first known case of parametrial anisakidosis in a 42-year-old woman and review existing literature.

Gastrointestinal bleeding due to suspected anisakiasis: challenging differential diagnosis for a rare disease

As compared with Eastern countries, the incidence of gastrointestinal diseases caused by the ingestion of nematode eggs is very low in Europe, in spite of the fact that the consumption of raw fish has increased in these countries as well in recent years. The authors present here, a rare case of gastrointestinal bleeding due to Anisakis simplex. This is a very uncommon clinical presentation which rise several problems in diagnosis and management.

Peritoneal manifestations of parasitic infection

The purpose of this study was to describe of peritoneal manifestations of parasitic infection at CT. A broad spectrum of CT findings can be seen in the peritoneal cavity, including a varying degree of omental or mesenteric infiltration, single or multiple peritoneal mass or nodule, and peritoneal thickening or stranding. Recognition of these findings are crucial for establish an early diagnosis and helps avoid unnecessary surgery.

Chronic Gastric Anisakiasis Presenting as Pneumoperitoneum

Typically, the diagnosis of gastric anisakiasis is made at endoscopy with the identification of anisakis larvae. We report a case of gastric anisakiasis presenting as pneumoperitoneum. A 70-year-old Japanese woman was admitted to our hospital with abdominal fullness and pain. Plain chest X-ray in the upright position showed the presence of free gas below the diaphragm. A tentative diagnosis of perforation peritonitis was made and an emergency laparotomy was performed. At laparotomy, a 4 cm, circumscribed red mass was noted on the anterior wall of the upper body of the stomach near the lesser curvature and a partial gastrectomy was carried out. The histological diagnosis showed a foreign body, assumed to be a part of anisakis larvae, seen in the centre of the granuloma. On the serosal aspect, there was histological evidence of peritonitis with fibrin and neutrophils. In addition, an antianisakis larvae immunoglobulin G antibody test was positive. Chronic gastric anisakiasis was suspected because of the presence of eosinophilic granuloma in the resected area and denatured anisakis larvae. Thus, we interpret this case as gastric perforation acutely based on chronic gastric anisakiasis.

Gingivostomatitis after eating fish parasitized by Anisakis simplex: a case report

Anisakis simplex (AS) is a nematode that may be encountered as a parasite in various kinds of seafood. Human beings may accidentally acquire AS larvae by eating raw or undercooked seafood. In addition to human parasitization (anisakiasis), this nematode can induce allergic reactions. AS-related diseases are frequent, especially in those countries with a high level of fish consumption and with traditions of eating raw or undercooked seafood. To our knowledge, this is the first report of gingivostomatitis secondary to the ingestion of fish with AS parasites.

[Gastrointestinal anisakiasis. Study of a series of 25 patients]

INTRODUCTION

Infection with the parasite Anisakis simplex is common in Japan and northern European countries. The number of reported cases in Spain has increased since the first description in 1991. The aim of the present study was to evaluate the incidence, clinical patterns, histopathological lesions, treatment, and outcome of Anisakis simplex infection in our environment.

MATERIAL AND METHOD

Cases of gastrointestinal anisakiasis diagnosed in our center from December 1999 to January 2002 were studied. Only patients with detection of the parasite in oral endoscopy or the surgical specimen and those with elevated levels of specific IgE to Anisakis simplex, a clinical picture compatible with anisakiasis, or a history of raw fish intake were included. Epidemiological, clinical and laboratory data, as well as diagnostic, histopathologic and therapeutic features, and outcome in these patients were recorded.

RESULTS

Twenty-five cases of gastrointestinal anisakiasis were diagnosed during the study period, representing an incidence of 3.87 cases per 100 000 inhabitants/year. All the patients had ingested raw anchovies. Two groups were observed. The first group was composed of 10 patients with a gastric form of the infection, in which the main symptom was epigastralgia (90%). Oral endoscopy was performed in all patients and the parasite was detected in five (50%). The second group was composed of 15 patients with intestinal involvement in which the main manifestations were symptoms mimicking appendicitis (80%). The most frequent finding of laparotomy and/or imaging tests (abdominal ultrasonography, intestinal transit, abdominal CAT) was terminal ileitis (80%). Seven patients underwent surgery: intestinal resection was performed in four with detection of Anisakis simplex in three. Eosinophilic infiltration was found in all surgical specimens. Treatment was symptomatic in most of the patients and outcome was favorable in all.

CONCLUSIONS

Infection with Anisakis simplex should be investigated in patients with abdominal pain after intake of raw fish, ileitis of unclear origin, or eosinophilic gastroenteritis.