The content published in Cureus is the result of clinical experience and/or research by independent individuals or organizations. Cureus is not responsible for the scientific accuracy or reliability of data or conclusions published herein. All content published within Cureus is intended only for educational, research and reference purposes. Additionally, articles published within Cureus should not be deemed a suitable substitute for the advice of a qualified health care professional. Do not disregard or avoid professional medical advice due to content published within Cureus. Introduction ============ Acute abdominal pain is an alarming complaint for a young patient. It may be difficult to differentiate between acute appendicitis and a similar-looking abdominal mass. However, appendicitis should be included in the list of possibilities of such an acute abdomen. Case presentation ================= A 30-year-old Caucasian male presented to our emergency department complaining of acute onset left upper quadrant abdominal pain for the past two days. Patient history was non-contributory except for tobacco use. Physical examination revealed a moderately tender, palpable, and immobile mass. A CT scan (Figure [1](#FIG1){ref-type="fig"}) revealed a large mass in the left iliac fossa with associated lymphadenopathy. {#FIG1} Pediatric surgery consulted and recommended surgical removal of the tumor. In view of the patient's reluctance, the decision was made to refer to the urology department. Urology performed a transperineal ultrasound, which revealed a 5-cm x 3-cm x 4-cm mass in the bladder dome with adjacent ureteral obstruction and a normal-sized appendix with normal walls. The diagnosis of left ovarian mass with ureteral involvement and acute appendicitis was made. The patient was taken to the operating room and underwent laparotomy. During the procedure, the mass was found to be inseparable from the bladder dome. There was no perforation of the mass, and it was removed in total. No lymphadenopathy was noted in the pelvic area; therefore, no lymph node dissection was performed. The patient's hospital stay was uneventful, and the patient was sent to the oncology department with a plan for the next cycle of chemotherapy. Discussion ========== Ovarian masses and acute appendicitis share similar presentation. Both share abdominal tenderness, periumbilical abdominal pain, nausea, vomiting, fever, and rarely leukocytosis. In case of ovarian mass, the appendix is often adherent to the ovary. Occasionally, acute appendicitis can present as an acute abdomen. In such cases, differential diagnosis between acute appendicitis and a large ovarian mass can be a challenge for the first-line physician. The incidence of ovarian neoplasms in women of reproductive age is 7% \[[@REF1]\]. Approximately 50% of malignant ovarian tumors are found in premenopausal women \[[@REF1]\]. However, the incidence of the coincidence of appendicitis with an ovarian mass is limited to only four cases of 10,000 hospitalizations reported in a 10-year period \[[@REF2]\]. Since ovarian masses are frequently detected incidentally on sonography in asymptomatic women, they must be considered as a differential diagnosis of acute abdominal pain. Therefore, such cases should be handled with extreme caution. Appendicitis and adnexal torsion can have identical presentation. However, patients often present earlier with abdominal pain. Acute appendicitis is known to present with an acute onset of pain; it is typically less than 72 hours and, therefore, requires urgent surgical intervention \[[@REF3]\]. Our patient had a longer interval between onset of symptoms and surgery (14 days). As described by Kheder, one must not postpone surgical intervention even in cases of acute appendicitis \[[@REF4]\]. CT is the best imaging study for such cases. CT of the abdomen will help in determining whether the mass is an appendiceal abscess, a hemorrhagic cyst, a dermoid cyst, or a mature teratoma. In contrast, CT cannot be used to distinguish between an ovarian mass and a hydrosalpinx because both of them show a high density as compared to a normal appendix. Conclusions =========== In conclusion, this case illustrates an unusual clinical scenario in which appendicitis was found coinciding with a pelvic mass. Therefore, a broad differential diagnosis, including acute appendicitis in young patients, should be kept in mind for all masses. The authors have declared that no competing interests exist. Consent was obtained by all participants in this study