Uveal Melanoma Biopsy: A Review

Abstract

Intraocular tumor diagnosis is based on clinical findings supported by additional imaging tools, such as ultrasound, optical coherence tomography and angiographic techniques, usually without the need for invasive procedures or tissue sampling. Despite improvements in the local treatment of uveal melanoma (UM), the prevention and treatment of the metastatic disease remain unsolved, and nearly 50% of patients develop liver metastasis. The current model suggests that tumor cells have already spread by the time of diagnosis, remaining dormant until there are favorable conditions. Tumor sampling procedures at the time of primary tumor diagnosis/treatment are therefore now commonly performed, usually not to confirm the diagnosis of UM, but to obtain a tissue sample for prognostication, to assess patient's specific metastatic risk. Moreover, several studies are ongoing to identify genes specific to UM tumorigenesis, leading to several potential targeted therapeutic strategies. Genetic information can also influence the surveillance timing and metastatic screening type of patients affected by UM. In spite of the widespread use of biopsies in general surgical practice, in ophthalmic oncology the indications and contraindications for tumor biopsy continue to be under debate. The purpose of this review paper is to critically evaluate the role of uveal melanoma biopsy in ophthalmic oncology.

Keywords: biopsy; fine needle aspiration biopsy; metastases; prognosis; uveal melanoma.

Figure 1

(A) Fundus photograph and (B) blue (C) and infrared autofluorescence of a case of a macular small uveal melanoma characterized by (A–C) diffuse orange pigment on its surface and (B,C) serous retinal detachment. The thickness of this lesion measured by spectral domain optical coherence tomography was 550 μm.

Figure 2

Fluorescence in situ hybridization (FISH) analysis with centromeric probe for chromosome 3 of tumor material obtained by fine needle aspiration biopsy in a case of uveal melanoma. (A) Normal cells with two red signals corresponding to two chromosomes 3. (B) Monosomy 3: cells with one red signal have lost one chromosome 3.

Figure 3

A case of post enucleation histologically proven diffuse retinoblastoma in an 8-year old child. Note (A) the anterior chamber invasion and (B) the increase retinal thickness of the detached retina in the B-Scan examination. (B) No calcifications are detectable by ultrasound.

Figure 4

Fine needle aspiration biopsy sample: transscleral approach in a posterior uveal melanoma. Our standard fine needle aspiration biopsy (FNAB) procedure is performed using a 25 gauge (25 mm in length) spinal needle connected to a 10 cc syringe by a hollow tube. (A) The needle is inserted into the tumor trough a partial scleral incision (to avoid excessive pressure when penetrating the eye) (Figure 1). (B) The scleral suture (7.0 Polyglactin) is prepared before the needle insertion. (C) A double-pass or multiple-pass sampling is often performed through the same scleral access. (D) The scleral incision is then sutured and the radioactive plaque immediately placed over the tumor base.

Figure 5

(A) A case of diffuse iris melanoma characterized by anterior chamber angle infiltration. (B,C) Aqueous tap of the same case confirming the diagnosis of spindle cell iris melanoma.

Figure 6

(A,B) A case of iris metastasis characterized by (A) multiple anterior chamber angle nodules in a patient previously treated by surgery and systemic chemotherapy because of a breast carcinoma (ductal type). (B) Intraocular fine needle aspiration biopsy of the same case confirming the diagnosis of iris metastasis from breast carcinoma. (C,D) A case of (C) iris partially amelanotic melanoma confirmed at cytology by (D) fine needle aspiration biopsy.

Figure 7

Fluorescence in situ hybridization analysis (FISH) in a case of posterior uveal melanoma sampled by fine needle aspiration biopsy. (A) FISH with locus specific probe for MYC gene (red) and for the centromere of chromosome 8 (light blue) confirmed the gain of 8q24 showing three copies of MYC gene in each cell; (B) The same case was also characterized by monosomy 3: cells with a single red hybridization signal have lost one chromosome 3.

Figure 8

Multiplex Ligation Probe Amplification analysis in a case of posterior uveal melanoma sampled by fine needle aspiration biopsy. The tumor is characterized by losses on the chromosome 1p, 6q and all along the arm of chromosome 3, including the centromeric region until 3p14; gains were also present in the 6p and 8q regions, with an amplification of the MYC gene (8q24.12–8q24.13).

Figure 9

Fine needle aspiration biopsy sample in a medium sized posterior uveal melanoma: a large number of cells is obtained and collected in a vial with the culture medium Roswell Park Memorial Institute (RPMI) 1640 (Euroclone Life Science, Pero-MI, Italy) before the genetic analysis. The obtained material is visible in the vial as a brown deposit at the bottom of the tube.

Figure 10

Posterior uveal melanoma prognostic test flow-chart modified from Schopper et al. [85]. Large and anterior tumors are commonly biopsied using a trans-scleral approach, whereas posterior tumors and small tumors are better reached by a transvitreal approach. When possible, FNAB (fine needle aspiration biopsy) should be used because it is considered to be the less invasive technique. Current prognostic tests rely on either DNA or RNA extraction from tumor specimens. FISH (fluorescence in situ hybridization), CGH (comparative genomic hybridization), MLPA (multiplex ligation-dependent probe amplification), and karyotyping are the most common used techniques for the DNA analysis. GEP (gene expression profiling) is the preferred technique for the RNA-based prognostication. An estimated 10-year metastasis-free survival is listed based on publications on the karyotype analysis [86], FISH [87], and MLPA [88]. An estimated 5-year metastasis-free survival based on GEP classification is also listed [89].