Granuloma of the liver due to Enterobius vermicularis. Report of a case

[Multilocular hepatic masses due to Enterobius vermicularis]

Infestation with Enterobius vermicularis involving extraintestinal manifestation is rare. In a 50-year-old man with lower abdominal pain, computed tomography led to a suspected diagnosis of sigmoid carcinoma with liver metastasis. After ruling out colon cancer by endoscopy, laparoscopic resection of one suspected tumor nodule in the liver was performed. Histopathological examination revealed parasitic granulomas containing pinworms. Hematogenous migration was postulated in the setting of phlebitis with thrombosis of the inferior mesenteric vein.

Enterobious vermicularis induced infectious keratitis following penetrating keratoplasty

A 28-year-old man with a prior history of penetrating keratoplasty in the left eye for total corneal melt presented with a 3-day history of a red, painful left eye. On examination, he was found to have graft infiltrates. Microscopic examination of wet mount preparation of corneal scrapings revealed the presence of embryonated eggs of E. vermicularis. Cellophane (scotch) tape preparation from perianal region also revealed embryonated eggs of E. vermicularis as well as live adult worms. Ocular and adnexal involvement by E. vermicularis is extremely rare. Here, we report the first case of infection of a corneal graft with E. vermicularis.

Unusual Etiology for Transaminitis

An infection with Enterobius vermicularis (pinworm) commonly affects the gastrointestinal (GI) tract. The ectopic localization of an enterobius infectious is rare, especially in the liver. We report the case of a 37-year-old man who presented to the gastroenterology clinic with abdominal pain and was found to have elevated transaminases. Workup for acute/chronic liver disease was unrevealing. He underwent endoscopic evaluation showing a live pinworm in the colon. He was treated with albendazole with improvement in GI symptoms and resolution of his transaminitis. There are scarce reports in the literature describing pathognomonic, clinical, imaging, and laboratory findings for pinworm infection. Here, we attempt to review the literature for hepatic involvement with an enterobius infection and discuss the findings via this case.

A preliminary epidemiological study of pinworm infection in Thaklong Municipal Early Childhood Development Center and Rangsit Babies' Home, Pathum Thani, Thailand

Objectives

We investigated the prevalence and risk factors for Enterobius vermicularis in children at the Thaklong Municipal Early Childhood Development Center (TMECDC), and the Rangsit Babies’ Home (RBH) in Pathum Thani, Thailand using the Scotch tape method.

Results

397 children aged 3–6 years were sampled (male = 198); 31 (7.8%) were E. vermicularis positive: 1 (TMECDC) and 30 (RBH). 264/397 (66.50%) of parents had incomes > 12,000 baht/month and 313/397 (78.84%) were educated from primary school to college. Univariate analysis identified (i) age 5–6 years, (ii) female sex, (iii) lower education of mother/father, (iv) being a house wife, (v) being a low income family, (vi) being resident in the orphanage, (vii) reporting anorexia and/or fever, and (viii) not washing their bottoms as factors for a positive slide. By logistic regression, education level and age group were independently associated with a positive Scotch tape result. Older children and higher family education had opposing associations with E. vermicularis. Strategies to control pinworm infection should focus on high-risk children in orphanages.

Enterobius vermicularis presentation during laparoscopic cholecystectomy

Enterobius vermicularis infection is uncommon in adults, compared to children, and rarely causes significant illness. Adult infection is usually colonic in nature and found incidentally at colonoscopy. Worm migration to other tissues is rare. We here-in describe the case of a 73-year-old woman found to have biliary tree E. vermicularis—an as yet undescribed site of migration.

Enterobius vermicularis infection of the liver in a patient with colorectal carcinoma with suspected liver metastasis

A 68-year-old man diagnosed with cT3N2 adenocarcinoma of the rectum presented with a synchronous solitary liver metastasis on CT scan. Neoadjuvant chemoradiotherapy was started to downstage the primary tumour. Resection of the rectal tumour followed 3 months after the last radiotherapy session and primary resection of the isolated liver lesion was performed in the intervening period. Histopathological assessment of the liver lesion, however, showed no malignancy, but did reveal a necrotic infection due to Enterobius vermicularis. This parasite is frequently found in the intestines, but only rarely infects the liver. The patient was subsequently treated with the anthelmintic drug mebendazole 100 mg once a week for 2 weeks. Histopathological assessment of the rectal specimen showed complete regression after neoadjuvant chemoradiotherapy without evidence of remaining E. vermicularis, suggesting pinworm eradication. The patient recovered promptly after both surgical procedures.

Unusual presentation of Enterobius vermicularis in conjunctival sac

We report an unusual case of extraintestinal infection with adult Enterobius vermicularis worms in the conjunctival sac of a two-and-a-half year old boy from Alipurduar, West Bengal, India. Only two other similar cases have been reported in the English literature, one from Assam, India in 1976, and the other from Illinois and California in 2011.

Enterobius vermicularis (pinworm) infection of the liver mimicking malignancy: Presentation of a new case and review of current literature

INTRODUCTION

Enterobius vermicularis or "pinworm" infection of the liver is an extremely rare condition with only five cases previously reported in literature. It is characterized by the presence of granulomas in the liver with a necrotic core, containing adult helminthes or their ova. Because of the relatively mild symptomatology associated with this disease, prior to the arrival of modern imaging methods hepatic enterobiasis was an incidental intra-operative finding during abdominal surgery for other conditions. In recent years however, with high-resolution abdominal imaging readily available and the improved safety of hepatic resection, a lower threshold for treating suspicious hepatic nodules aggressively with surgery is being adopted.

PRESENTATION OF CASE

We present the second case in international literature, where E. vermicularis of the liver was mistaken for malignancy and led to hepatic resection and perform a literature review of the five previously documented cases of hepatic enterobiasis.

DISCUSSION

Our report identifies certain trends in this condition's aetiology and clinical behaviour, but due to its rarity definitive answers cannot yet be established.

CONCLUSION

We do not advocate a change in the current approach of suspicious hepatic nodules, but we do feel that better understanding of the mechanisms involved with hepatic enterobiasis could, in the future, prevent unnecessary surgery.

Enterobius vermicularis in a 14-year-old girl's eye

We report an unusual case of extraintestinal infection with adult Enterobius vermicularis worms in the nares and ocular orbit of a 14-year-old girl in Illinois. Only one other similar case has been reported in the English-language literature.

Enterobious vermicularis (pinworm) infestation of the vulva: report of 2 cases of a pseudoneoplastic lesion mimicking squamous carcinoma

Enterobious Vermicularis (pinworm) infestation outside the gastrointestinal tract is rare. We report 2 patients with vulval involvement, one of whom presented with a clinically suspicious, rapidly growing mass. The histology of both lesions showed similar features of epidermal proliferation in the form of hyperkeratosis, acanthosis, and papillomatosis; this pseudoepitheliomatous hyperplasia raised the possibility of a well-differentiated squamous carcinoma. There was associated inflammation in both cases, including large numbers of eosinophils in 1 case. On the surface or within the keratin layer, structures with the morphology of enterobious vermicularis eggs were identified. In reporting this unusual pseudoneoplastic phenomenon, we stress the necessity for the pathologist to consider and look for parasites in proliferative squamous lesions of the vulva, especially when there is an associated inflammatory infiltrate rich in eosinophils.

Enterobiasis in ectopic locations mimicking tumor-like lesions

Both the clinical and the histopathological diagnostic difficulties of oxyuriasis in unusual sites and their importance from a clinical point of view are pointed out. The authors report two ectoptic cases of enterobiasis observed in Northern Italy, one located in a fallopian tube of a 57-year-old woman and the other in a perianal subcutaneous tissue of a 59-year-old man, mimicking tumor-like lesions. The authors take advantage of the occasion to focus the attention of the medical world on this subject, lamenting the scarce importance given to this parasitosis in university courses of medical schools and in medical textbooks as it is incorrectly considered “out-of-fashion.”

Impact of health educational programmes on the prevalence of enterobiasis in schoolchildren in Thailand

Enterobiasis is a worldwide prevalent disease particularly in low income areas. The budget needed for the prevention, treatment and eradication of the disease has thus far frustrated the limited budgets of global public health systems. A study was undertaken to determine if education in addition to medical treatment of enterobiasis could make a difference to the rates of infection. A total of 777 children (399 male and 378 female) from 11 elementary schools in five districts of Samut Prakan Province, Thailand were examined between December 2000 and March 2002. In five of the 11 schools studied, medical treatments were applied, followed by a programme of educating the children in the prevention of infection. Children in the remaining six schools received medical treatment only. The study showed a decrease in infections among children who received supplementary education. This decrease was significant in comparison to the decrease shown among children who received medical treatment only. The study therefore showed that educating high risk individuals played a key role in the prevention of enterobiasis.

A case of ovarian enterobiasis

A 36-year old Korean woman consulted a clinic for a regular gynecological examination, and a mass was noticed in her pelvis. She was referred to the Asan Medical Center, Seoul where transvaginal ultrasonography confirmed a pelvic mass exceeding 10 cm in diameter. She received total abdominal hysterectomy and bilateral salpingoophorectomy, and a borderline serous neoplasm with micropapillary features involving the left ovary and right ovarian serosa was histopathologically confirmed. In addition, a section of a nematode with numerous eggs was found in the parenchyma of the left ovary. The worm had degenerated but the eggs were well-preserved and were identified as those of Enterobius vermicularis. She is an incidentally recognized case of ovarian enterobiasis.

Chemotherapy of enterobiasis (oxyuriasis)

Enterobius vermicularis (syn. Oxyurus vermicularis), also known as pinworm or seatworm, is the causative agent of human enterobiasis (oxyuriasis). The disease is more prevalent in temperate regions and is facilitated by factors such as overcrowding in schools and family groupings, as well as inadequate personal and community hygiene. Although the infection is more likely to occur in lower socioeconomic groups, enterobiasis has been reported to affect virtually every level of the general population and especially children. In the great majority of cases, enterobiasis is asymptomatic. One common symptom is intense pruritus ani that in some patients can lead to insomnia, restlessness and irritability. Scratching may cause skin irritation, and in more serious cases, eczematous dermatitis, haemorrhage or secondary bacterial infections. Ectopic migration of E. vermicularis often results in pinworm infestation of the female genital tract often causing granulomas of the uterus, ovary and the fallopian tubes and pelvic peritoneum. Anthelmintic therapies for enterobiasis are successful and include mebendazole, albendazole and pyrantel pamoate. Mass medication of affected groups reduced symptoms rapidly, progressively and in a cost-effective way.

Enterobiasis: a histopathological study of 259 patients

Enterobius worms or their eggs, or both, are present in preserved tissue sections or tissue specimens of 259 patients whose medical records are on file at the Armed Forces Institute of Pathology, Washington D.C., U.S.A. The most common site of infection (86.5%) was found to be the lumen of the appendix, where the worms provoke no reaction. Of the 259 patients 11 (4.2%) had worms and/or eggs in granulomas of the abdominal and pelvic peritoneum, and an equal number had granulomas on the peritoneum of the salphinx or on the surface of the ovary. There were also ectopic worms and/or eggs in granulomas on the peritoneum of the small and large intestines (2.7%). These Enterobius granulomas form around degenerating adult worms, around discrete eggs, around clusters of eggs, and, we believe, also around the tracks of migrating worms. Three patients (1.2%) had worms in perianal abscesses. A necrotic granuloma, removed from the lung of one patient, surrounded a degenerating adult worm. This suggests that the worm, carried to the lung as an embolus, impacted in a pulmonary arteriole. A stool specimen of one patient contains eggs of Enterobius, and that of another patient contains an adult Enterobius. This is the largest recorded histopathological study of enterobiasis in man.

The presence of pinworms (Enterobius sp.) in the mesenteric lymph nodes, liver and lungs of a chimpanzee, Pan troglodytes

This report describes a case of fatal enterobiasis caused by Enterobius sp. in the mesenteric lymph nodes, lymphatic vessels of mesentery, blood vessels of the liver and lungs of a chimpanzee from Qingdao Zoo, China. Based on pathological findings, it is likely that the pinworms obtained access to these organs via the lymphatic or haematogenous pathway. As far as we are aware, this is the first reported case of Enterobius sp. in the mesenteric lymph nodes and blood vessels of the lungs and veins of the hepatic triad in a chimpanzee.

Granuloma of the anal canal due to Enterobius vermicularis. Report of a case

A case of a submucosal foreign body granuloma caused by Enterobius vermicularis in the wall of the anal canal of a 29-year-old man is reported.

Oxyuris granulomas of pelvic peritoneum and appendicular wall

Infestation with Enterobius (Oxyuris) vermicularis is very common but seldom produces lesions and even more rarely causes granulomas. Two cases of oxyuris granulomas/nodules), one in the serosa of ovaries and left fallopian tube in a female of 32-years and the other in the submucosa of the appendix in a 10-year old girl are identified by the presence of true necrotizing granulomas containing the parasite. The pathogenesis and differential diagnosis of abdominal granulomas is discussed.