Appendiceal tumors are very rare and metastatic lesions to the appendix are extremely uncommon. Metastases or direct invasion by a separate primary malignancy account for 77.2% of all pathologically confirmed appendiceal malignancies . A metastatic lesion to the appendix may be diagnosed incidentally, but the increase in size of a metastatic lesion may cause stenosis or obstruction of the lumen of the appendix, which can lead to the development of appendicitis . An extensive literature search identified just one report of squamous cell carcinoma of the uterine cervix with metastasis to the appendix. . To the best of our knowledge, this is the first report of adenocarcinoma of the uterine cervix metastatic to the appendix.
Tumors of the appendix that are not obviously of appendiceal origin should prompt a search for other primary tumors. It is important to review the complete history, gastrointestinal endoscopy, gynecologic examination and PET–CT, because the most commonly reported lesions are from ovary, colon stomach and lung [2, 3]. In the case of a patient with a previous malignancy but a negative clinical examination and imaging studies, pathological findings from the previous malignancy may give important clues to the diagnosis. In the present patient, CK7 positive and CK20 negative immunohistochemical studies were consistent with her previous cervical cancer and the rate of ER and PgR positivity were the same as the previous cervical cancer, establishing the origin of the lesion found in the appendix.
The majority of cervical cancer recurrences are found within 2 years of the original diagnosis . The most frequently observed metastatic sites are lung, para-aortic lymph nodes, abdominal cavity and supraclavicular lymph nodes . In the present patient, metastasis to the appendix occurred 16 years after hysterectomy and irradiation, which is an extremely rare situation. To the best of our knowledge, there are no reports of a recurrence more than 10 years after treatment of cervical cancer. In fact, 89 to 99% of recurrences are detected within 5 years of treatment . In the present patient, while the interval is unusually long, we believe that the histologic appearance and the immunohistochemistry strongly support the diagnosis of a metastatic lesion. Given the histologic and immunohistochemical evidence of a lesion found in the appendix that looks very different from appendiceal tissue and the same as her previous lesion, we believe that it is a metastatic lesion as described. It is conceivable that there could be another origin, although there is no evidence of such an origin. Kawabe et al. reported recurrent advanced gastric cancer diagnosed 20 years after partial gastrectomy and considered that delayed recurrence was related with the balance between cancer cell proliferation and apoptosis when the amount of residual cancer cells is very small after treatment . In the present patient, because it was possible that the balance was stable, the metastasis did not develop and was controlled in the appendix.
Most patients with metastases from cervical cancer are not curable by resection, but some have disease that is isolated to the lymph nodes or a limited area and are candidates for surgical resection. Complete resection of a metastatic appendiceal tumor without other metastases has no influence on the prognosis .