84 - Freie Mitteilung
17. Mai 2019, 08:15 - 09:45, Bellavista 5, 6. OG
Infiltrating non-hodgkin lymphoma – Rare differential diagnosis of a tumor in the vermiform appendix
S. Taha-Mehlitz, J. Bockmeyer, E. Memeti, M. Nowack, J. Metzger, J.-M. Gass, Presenter: E. Memeti (Lucerne)
Approximately 4-9 % of all lymphomas are mantle cell lymphomas (MCL). They affect the gastrointestinal tract in about 25 %. Whereas the colon is the most common site of gastrointestinal MCLs, presenting with polypoid lesions, the appendix is a rare location and is usually involved by continuity of ileocecal disease. In general clinical findings are variable. Abdominal pain, sometimes mimicking acute appendicitis, gastrointestinal bleeding or non-specific symptoms may cause delayed diagnosis. One third of patients with MCL present with systemic B symptoms. We report a case of Non Hodgkin lymphoma as an incidental finding in gynaecological laparoscopy for suspected ovarian tumor.
A 57-year-old woman presented with diffuse abdominal pain in the right lower abdomen since several months. The pain was increasing while sitting, she also suffered from hot flushes and diarrhea. First seen by gynaecologists, endovaginal ultrasound showed a solid tumor measuring 10x5x6.5 cm, with inhomogeneous structure, suspicious of ovarian tumor. Diagnostic laparoscopy revealed a strongly thickened vermiform appendix with massive mesenterial and retroperitoneal lymphadenopathy as well as peritoneal nodules. Since low grade appendiceal mucinous neoplasm or neuroendocrine tumor were possible differential diagnosis a midline laparotomy and right-sided hemicolectomy with oncological central lymph node resection was performed.
Histopathology revealed a blastoid MCL infiltrating the appendix. The immunohistochemical pattern was positive for CD20, CD5, Cyclin D1, bcl-6 and MIB-1 up to 75 %. The postoperative course was uneventful and the patient was discharged eleven days after surgery. Staging was completed with positron emission tomography/computed tomography and bone marrow biopsy. Polychemotherapy was conducted within a study protocol afterwards. Although exact radiological data is lacking, diffuse mural soft-tissue thickening with appendiceal diameter about 2.5 cm in the CT scan may rise the suspicion of lymphoma, but there are no pathognomonic patterns. Therefore, the diagnosis is usually confirmed histopathologically.
Infiltrating mantle cell lymphoma causing appendiceal tumor is a rare differential diagnosis of right lower abdominal pain and should always be considered preoperatively, especially in cases of conspicuous imaging.