Case Presentation: The patient is a 43 year old woman with Hashimoto’s thyroiditis, Addison’s disease, and ovarian cysts who presented with days of focal right lower quadrant pain and one day of nausea, vomiting, and fever. She had no diarrhea, hematochezia, dysuria, or urinary frequency/urgency. She had doubled her maintenance glucocorticoid dose as instructed when feeling unwell. Vitals at presentation showed a temperature of 39.2 C, heart rate of 120, blood pressure of 104/53, and adequate saturations on room air. Her abdomen was soft but tender in the right lower quadrant with voluntary guarding. There was no rebound tenderness or distention. Labs showed bicarbonate was 19, Cr was 1.44, liver function tests were normal, lactate was 1.9, TSH was 6.04, and white count was 9.9. Pregnancy test was negative. CT abdomen/pelvis showed colonic diverticula and a significant inflammatory process in the right lower quadrant involving the cecum and pericecal tissue that obscured the appendix, but there was no free air or definite periappendiceal abscess. The patient was evaluated by general surgery and admitted to the hospital medicine service for conservative management due to potential surgical morbidity given the degree of cecal inflammation present. The differential diagnosis included complicated appendicitis, underlying malignancy, inflammatory bowel disease, or atypical infection. Antibiotics were administered and the patient was discharged to home four days later after symptoms had improved. Colonoscopy was performed one month later and showed a normal cecum. Laparoscopic appendectomy was performed four months after presentation due to concern that imaging would not have shown a small tumor or polyp occluding the appendiceal lumen. The appendix was dilated to one cm in diameter but otherwise appeared normal, but ten small lesions were discovered on the peritoneum that appeared consistent with endometriosis. Pathology confirmed endometriosis involving the appendix.

Discussion: Hospitalists frequently care for patients presenting with abdominal pain. Endometriosis most commonly affects the fallopian tubes, ovaries, and immediately surrounding tissue, causing pelvic pain that is usually concomitant with menses. Rarely, endometriosis affects more distant organs, including bowel. The presenting patient in this case had significant cecal inflammation that led to a wide differential, including malignancy. The patient had no known history of endometriosis, so this was not considered by the primary team or several consulting teams until surgical intervention revealed the diagnosis. The patient’s clinical outcome was not negatively impacted by the delayed diagnosis, but she endured months of uncertainty with a potential diagnosis of malignancy.

Conclusions: Undifferentiated abdominal pain is often managed by the hospitalist when surgical intervention is not warranted. Gynecologic disease, including atypical presentations of such disease, should be considered in all female patients presenting with acute abdominal pain, regardless of history.