Ingestion of foreign bodies, particularly fish bones, is a common clinical scenario. In most cases, foreign bodies pass spontaneously without complications; however, in very rare cases (less than 1%), they can lead to intestinal perforation (2).The occurrence of such a complication in the appendix is exceptionally low, with reported incidences ranging from 0.005% to 0.11% (3). The rarity of perforated appendicitis caused by fish bones, estimated to be less than 0.0005%, makes this case noteworthy (3). The use of CT imaging is crucial in identifying the foreign body within the appendiceal lumen, guiding the diagnosis and successful laparoscopic appendectomy. We report a case of a young female presenting with abdominal pain, diagnosed with fishbone-induced acute appendicitis and was successfully treated with laparoscopic appendectomy.

A 26-year-old female presented to the emergency department with a 3-day history of right lower abdominal pain, accompanied by nausea and vomiting. There was no history of diarrhea, irregular menstrual cycles, urinary symptoms, or vaginal discharge. Clinical examination revealed localized tenderness in the right iliac fossa with positive rebound tenderness, raising concern for peritoneal irritation. She was afebrile (36.8°C), with a heart rate of 68 beats/min, oxygen saturation of 98%, and blood pressure of 106/68 mmHg. Her body mass index (BMI) was 22.

The laboratory findings of an elevated white blood cell count (12.01 x 10³/μL) with neutrophil predominance, along with an elevated C-reactive protein (CRP) level of 32.38 ng/dL, support an inflammatory process, likely infectious in origin. The unremarkable urine analysis further ruled out urinary tract issues as a cause of the patient's symptoms

The abdominal ultrasound findings were consistent with acute appendicitis, showing a non-compressible appendix measuring 8.0 mm in diameter with intraluminal echogenic shadows suggestive of debris and mild periappendiceal inflammation (Fig. 1).

A contrast-enhanced abdominal CT scan with multiplanar reconstruction demonstrated an enlarged appendix measuring 10 mm in diameter, along with the identification of a thin linear hyperdense structure within the appendiceal lumen (CT density of 95 to 104 HU), consistent with a foreign body, likely a fishbone. The tip of the hyperdense object extended through the appendicular wall into the mesentery and reaching the adjacent parietal peritoneum suggesting that the foreign body had caused perforation of the appendix.

The surrounding fat inflammation and the proximal appendiceal wall thickening further support the diagnosis of acute appendicitis with localized inflammation due to foreign body penetration. Despite the perforated appendix, CT revealed no extraluminal air or periappendiceal abscess. The distal portion of the appendix appearing normal likely indicates that the foreign body was lodged more proximally (Fig. 2). Other findings on the abdominal CT were unremarkable.

A final diagnosis of foreign body induced appendicitis with appendicular perforation was made. Based on the history and imaging characteristics of the foreign body, the possibility of a fishbone was raised.

The patient underwent laparoscopic appendectomy on the same day. Intraoperatively, a fishbone was found protruding through the proximal one-third of the appendicular wall with thickened inflamed appendix. Entire appendix with the fishbone was removed (Fig.3).

Ingestion of foreign bodies is a frequent clinical occurrence, with most passing through the gastrointestinal tract without complications (1). We report an unusual case of fishbone-induced appendicitis, which was successfully managed with prompt surgical appendectomy and foreign body removal. Clinical profile can mimic appendicitis, cholecystitis, bowel obstruction, malignancy (2). Acute appendicitis caused by foreign body impaction is a rare phenomenon, with the incidence of foreign bodies in the appendix reported to range from 0.005% to 0.11% (3). Many foreign bodies have been the cause of acute appendicitis including metallic objects, plant materials etc. (3). Foreign bodies, typically stiff or pointed objects, can inadvertently find their way into the appendiceal lumen, leading to obstruction, inflammation and in some cases, perforation (4). Because of the dependent position of appendix, foreign bodies migrate into the appendix and peristaltic movements are often insufficient to expel it back into the caecal lumen. Blunt foreign bodies cause acute appendicitis by blocking the lumen of the appendix, while sharp objects tend to cause inflammation by perforating the appendicular wall which can cause more serious complications such as appendicular abscess, perforation of adjacent organs, and peritonitis. Diagnosis can be made preoperatively with the help of CT abdomen with multiplanar reconstruction. Non-contrast CT can identify the hyperdense foreign body within the appendix.

Although gastrointestinal foreign bodies are relatively common, their passage into the appendix and subsequent development of appendicitis is an exceedingly rare condition. The patient’s history and clinical examination are often non-specific, which further complicates the diagnosis of appendiceal inflammation secondary to foreign body ingestion. Given the difficulty in making a clinical diagnosis, preoperative identification can often be successfully achieved through CT imaging of the abdomen. Once diagnosed, prompt surgical intervention, typically in the form of appendectomy and foreign body removal, can ensure effective treatment and prevent complications. This case highlights the importance of considering foreign body ingestion as a potential cause of appendicitis, even in the absence of a clear history of ingestion.