Appendiceal mucinous cystadenoma presenting as "porcelain" appendix with myxoglobulosis--a rare cause of a right lower quadrant mass.

Mucinous cystadenoma is a rare tumour of the vermiform appendix and is associated with cystic dilatation of the appendix, to which the more general term of mucocoele has been applied. Mucocoele of the appendix is only a descriptive term for abnormal mucus accumulation causing distension of the appendiceal lumen, irrespective of the underlying cause. Pre-operative diagnosis of appendix mucocoele, though infrequently made, is important as some of these lesions may be malignant, and also is essential in order to avoid the risk of rupture at surgery with subsequent development of pseudomyxoma peritonei. The appearances of mucocoele of the appendix and its uncommon variant of myxoglobulosis on plain radiograph, ultrasound and barium study are presented, together with review of the literature.