A rare case of clear-cell carcinoid of appendix

The carcinoids are the most frequent type of tumors arising from the appendix. In the majority of cases, these tumors are asymptomatic and usually are discovered after appendectomy. Definitive diagnosis relies on pathological examination of the resected appendix, size of the tumor being critical for the further management. Clear-cell change in neuroendocrine tumors (NETs) has rarely been described in the appendix. We choose to present a clear-cell carcinoid subtype of appendiceal NET to raise awareness on this potentially curable and rare condition that can be overlooked. We highlight the importance of the pathological exam and the morphological and immunohistochemical behavior of the tumor in confirming the diagnosis and aiding in the treatment decision making. Also, important entities should be considered in the process of differential diagnosis such as goblet-cell carcinoid or renal-cell÷ovarian carcinoma.