Unusual presentations of actinomycosis; anterior abdominal wall and appendix: report of three cases

Omental actinomycosis mimicking a foreign body infection

Actinomycosis is a chronic suppurative granulomatous disease caused by Actinomyces species. Abdominal actinomycosis is a rare condition and difficult to diagnose before surgery. Here, we report a case of omental actinomycosis mimicking a foreign body infection on computed tomography (CT). A 47-year-old man presenting with abdominal pain had a heterogeneous area comprising a 2-cm long linear radiopaque material with surrounding enhancing soft tissue density lesions and fat infiltrates, measuring 9 × 8 cm in the omentum of the right upper quadrant on CT. We assumed that the linear radiopaque material was a foreign body, such as a fish bone. Laparoscopy-assisted right hemicolectomy and partial omentectomy were performed under radiological suspicion of foreign body infection. Histological examination revealed the omental lesion to be actinomycosis. The patient was treated with antibiotics for 10 weeks, and he recovered well without any complication. Omental actinomycosis mimicking a foreign body infection is rare. The experience and knowledge regarding the variable CT findings of abdominal actinomycosis are useful because it should be differentiated from malignancy and other inflammatory conditions.

Intra-abdominal Actinomycosis Imitating Sigmoid Colon Cancer: A Case Report

Actinomycosis is a rare bacterial disease characterized by chronic or subacute suppurative inflammation. Abdominal actinomycosis is rarer and accounts for approximately 20% of all actinomycosis cases. In the literature, patients who underwent surgery for actinomycosis mimicking malignant tumors have been reported. Most of these patients had mucosal trauma and inflammation signs. It is often difficult to diagnose abdominal actinomycosis preoperatively and often impossible to distinguish it from a malignant tumor. We present a case that preoperatively was diagnosed as a malignant tumor but pathological evaluation reported to be diverticulitis and actinomycosis. This case can increase the awareness about this disease, which is possible to be treated non-surgically.

Actinomycosis of the omentum with invasion of the abdominal wall, small bowel and transverse colon mimicking malignancy

We report the case of a 59-year-old Russian man who presented with a painless, slow-growing, epigastric mass. CT revealed a large heterogeneous mass within the omentum infiltrating into adjacent tissues. During diagnostic laparoscopy, the omental mass was noted to be firm, raising the suspicion of malignancy. Surgical en-bloc resection of the mass, including the posterior rectus sheath, transverse colon and small bowel, was performed with primary anastomoses at laparotomy. Histological examination was inconsistent with malignancy and revealed the mass to be actinomycosis, confirmed by microscopy and gram staining. Surgical resection was followed by an 8-week course of penicillin and doxycycline antibiotic therapy. This treatment resulted in full clinical and radiological recovery with no complications. Although the clinical and radiological findings, in this case, were highly suspicious of malignancy, abdominal actinomycosis should be considered a differential diagnosis in patients with infiltrative abdominal masses and mild constitutional symptoms.

[Primary intestinal actinomycosis in ilium and colon. A case report and review of the literature]

Actinomycosis is a chronic, suppurative, inflammatory granulomatous disease caused by gram positive anaerobic filamentous bacteria of the genus Actinomyces, most frequently Actinomyces israelii. We report a case of a 42-year-old male presenting with abdominal pain, a 10kg weight loss and a fixed mass in the epigastrium. Tomography revealed dilatation of the intestinal loops and thickening of the colon walls; the coexistence of these two findings suggested a lymphoproliferative process. The tumour, ileum fragment and colon were surgically removed; these were adherent to the serosal fibro-adipose tissue. Microscopically, abundant polymorphonuclear infiltrate and grains of bacteria compatible with Actinomyces spp.were seen.

Actinomycosis, a lurking threat: a report of 11 cases and literature review

Actinomycosis remains characteristically uncommon, but is still an important cause of morbidity. Its clinical presentation is usually indolent and chronic as slow growing masses that can evolve into fistulae, and for that reason are frequently underdiagnosed. Actinomyces spp is often disregarded clinically and is classified as a colonizing microorganism. In this review of literature, we concomitantly present 11 cases of actinomycosis with different localizations, diagnosed at a tertiary hospital between 2009 and 2016. We outline the findings of at least one factor of immunosuppression in > 90% of the reported cases.

Actinomycosis presenting as an anterior abdominal mass after laparoscopic cholecystectomy

Abdominal actinomycosis is a rare disease caused by different anaerobic Actinomyces species. We report the case of a 55-year-old woman who presented with a painless, slow growing, left upper abdominal mass that developed after a laparoscopic cholecystectomy. A CT scan and MRI of the abdomen revealed a desmoid tumour of the left rectus abdominis muscle.Surgical excision was performed with an uneventful postoperative course. The histological analysis of the specimen was inconsistent with a desmoid tumour and revealed an infection of Actinomyces israelii in the anterior abdominal wall that was confirmed with a microbiology culture. The surgical treatment was followed by a course of penicillin antibiotic therapy for 6 months. This treatment resulted in full recovery with no further complications. Although it is rare, the patient's history of laparoscopic cholecystectomy was identified as the likely source of infection.

Abdominal Actinomycosis in Children: A Case Report and Literature Review

Abdominal actinomycosis is an uncommon pediatric infection that often manifests with a tumor-like lesion. We describe a previously healthy 11-year-old girl who presented with right lower quadrant abdominal pain and drainage. Computed tomography scan showed an abdominal wall mass. Surgical debridement cultures grew Actinomyces meyeri. Literature review identified 18 additional pediatric cases since 1964 that we have summarized.

Abdominal actinomycosis mimicking acute appendicitis

A 52-year-old Hispanic woman presented to the emergency department, reporting worsening sharp lower right quadrant abdominal pain for 3 days. CT of the abdomen and pelvis showed evidence of inflammation in the peritoneal soft tissues adjacent to an enlarged and thick-walled appendix, an appendicolith, no abscess formation and a slightly thickened caecum consistent with acute appendicitis. During laparoscopic appendectomy, the caecum was noted to be firm, raising suspicion of malignancy. Surgical oncology team was consulted and open laparotomy with right hemicolectomy was performed. Pathology reported that the ileocaecal mass was not a malignancy but was, rather, actinomycosis. The patient was discharged after 10 days of intravenous antibiotics in the hospital, with the diagnosis of abdominal actinomycosis. Although the original clinical and radiological findings in this case were highly suggestive of acute appendicitis, abdominal actinomycosis should be in the differential for right lower quadrant pain as it may be treated non-operatively.