Biopsy of Iris and Anterior Chamber Tumours: Fine Needle, Minimally Invasive and Excision Techniques - Review.

Several benign, inflammatory and malignant lesions can present as iris or anterior chamber masses, including iris naevi, cysts, adenomas, leiomyomas, nodules, vascular tumours, melanomas, metastases, as well as iris and pigment epithelium adenocarcinomas. Fortunately, benign iris lesions are much more common than malignant tumours and many can be diagnosed by clinical and contemporary non-invasive analyses. However, differentiating between enlarging benign and malignant melanocytic lesions remains problematic. Anterior chamber and iris biopsy may include anterior chamber paracentesis and cytology, fine needle aspiration biopsy, vitreous aspiration cutter biopsy, micro-forceps and punch techniques, minimally invasive excision with an anterior chamber device and conventional iridectomy or excision biopsy. However, there may be reluctance from both patient and physician to progress to iris biopsy or excision biopsy as part of a definitive, or staged, management approach for fear of damage to delicate anterior chamber structures, or inadvertent spread of a malignant tumour. This review provides a practical guide to available techniques, highlighting indications, complications and outcomes. Notably, the yield for cytological, histological and cytogenetic results is typically high, significant complications are uncommon, and no cases of external tumour spread have been reported with clear corneal biopsy techniques.