Best cases from the AFIP: Trilateral retinoblastoma

Clinical and magnetic resonance imaging features of 14 patients with trilateral retinoblastoma

Background

Our study aimed to comprehensively investigate the age of onset, magnetic resonance imaging (MRI) features, and prognosis of children with trilateral retinoblastoma (TRB).

Methods

We included 14 patients with TRB diagnosed or followed up in our hospital. The age of onset and MRI features of the intraocular tumor and intracranial lesions were evaluated. A follow-up study was also conducted.

Results

A total of 11 participants were diagnosed with concurrent TRB at the age of 11.1±7.4 months, and 3 participants had late-onset TRB at age 37±19.1 months. The incidence of TRB with unilateral eye involvement was 7.1% (1/14). The intraocular tumors showed intense enhancement in contrast-enhanced T1-weighted images (WI) and significant diffusion restriction in diffusion WI (DWI) with an apparent diffusion coefficient (ADC) of (0.619±0.22)×10^-3 mm²/s. The intracranial lesions showed similar DWI aspects with an ADC value of (0.680±0.206)×10^-3 mm²/s. Therapeutically, 8 participants had a period of intraocular tumor stabilization and significant intracranial lesion volume reduction after chemotherapy, and 6 participants had given up treatment. Only 2 participants who simultaneously received high-dose chemotherapy and autologous hematopoietic stem cell rescue were still alive with no recurrence at 24 and 54 months of follow-up. The 1-, 2-, and 3-year overall survival (OS) rates were 80%, 18.75%, and 12.5%, respectively.

Conclusions

Patients with unilateral or bilateral RB can develop TRB. The intraocular and intracranial tumors showed slightly different ADC values. High-dose chemotherapy, combined with stem cell rescue can significantly improve survival. A long term and scheduled follow-up before 60 months of age is necessary for screening later-onset TRB patients.

Retinoblastoma in an Adult

Retinoblastoma is a rare malignant tumor of the retina usually seen in children before 5 years of age. The tumor is extremely rare in adults. We report here an unusual case of retinoblastoma in a 55-year-old adult female who presented to us with an orbital mass at a late stage of the disease. Detailed laboratory investigations and imaging studies could not make a precise diagnosis. The treating ophthalmologist suspected primary intraocular tumor, metastatic carcinoma, malignant melanoma, or lymphoma and referred the patient for fine needle aspiration cytology (FNAC). Cytopathological examination of Giemsa-stained FNAC smear was consistent with that of retinoblastoma and established the diagnosis.

Trilateral retinoblastoma: A systematic review of 211 cases

We conducted a systematic review of 72 studies to characterize trilateral retinoblastomas. Kaplan-Meier analysis was used to estimate survival, and statistical significance was assessed by using a log-rank test. We analyzed 211 cases of trilateral retinoblastomas. The average age of onset of retinoblastoma was 0.79 ± 1.38 years, and the average latency period between the onset of retinoblastomas and trilateral retinoblastomas was 1.49 ± 1.76 years. The brain tumors were found before the retinoblastoma diagnosis in 6 cases (3.1%), concurrently in 61 cases (32.1%), and after the retinoblastoma diagnosis in 123 cases (64.7%). Pineal tumors were found in 155 cases (73.4%) and sellar tumors in 46 cases (21.8%). The overall median survival was 10.3 months (95% CI, 8.5-13) and the 5-year survival rate was 15.7%. Central nervous system symptoms were variable and associated with shorter survival in univariate and multivariate analyses. The survival time in patients who received high-dose chemotherapy with stem cell transplant was significantly longer (p = 0.0067) than that of with or without conventional chemotherapy. Twelve long-term survivors were reported, and of these, six patients were treated with high-dose chemotherapy with stem cell transplant and six patients were treated with conventional chemotherapy. It is important that survivors continue to undergo regular medical surveillance in order to detect trilateral retinoblastoma at a potentially curative stage. Trilateral retinoblastoma patients with an irradiation history had shorter survival than those without irradiation history for retinoblastoma. High-dose chemotherapy should be considered as a potential treatment option for trilateral retinoblastomas.

Correlation of apparent diffusion coefficient at 3T with prognostic parameters of retinoblastoma

BACKGROUND AND PURPOSE

Pathologic prognostic parameters for retinoblastoma have been defined. Our purpose was to correlate ADC values at 3T with prognostic parameters of retinoblastoma.

MATERIALS AND METHODS

This study included 72 children (30 boys and 42 girls, mean age 19 ± 2.6 months) with retinoblastoma. Pretreatment diffusion-weighted MR imaging was performed on a 3T scanner with b factors of 0, 500, and 1000 seconds/mm(2). ADC values were calculated and pathologic specimens were analyzed. ADC values of the tumors were then correlated with prognostic parameters, including degree of histologic differentiation, tumor size, bilaterality, choroidal invasion, and optic nerve extension.

RESULTS

The mean ADC value of retinoblastoma was 0.49 ± 0.12 × 10(-3) mm(2)/s. The ADC values of well- and moderately differentiated tumors were significantly different (P = .007) from poorly and undifferentiated retinoblastoma. There was also a significant difference in the ADC value among small, medium, and large tumors (P = .015), as well as between unilateral and bilateral retinoblastoma (P = .001), and this was independent of the degree of differentiation. The ADC value was also significantly lower (P = .003) when optic nerve invasion was present. There was no correlation of ADC value with growth pattern or choroidal invasion (P = .640 and 0.661, respectively). The ADC value of retinoblastoma was well correlated with the degree of differentiation of the tumor (r = 0.87, P = .007) and inversely correlated with the size of the tumor (r = -0.68, P = .015).

CONCLUSIONS

ADC correlated with some of the accepted parameters of poor prognosis for retinoblastoma and may serve as a noninvasive prognostic parameter for assessment of newly diagnosed retinoblastoma.

Guidelines for imaging retinoblastoma: imaging principles and MRI standardization

Retinoblastoma is the most common intraocular tumor in children. The diagnosis is usually established by the ophthalmologist on the basis of fundoscopy and US. Together with US, high-resolution MRI has emerged as an important imaging modality for pretreatment assessment, i.e. for diagnostic confirmation, detection of local tumor extent, detection of associated developmental malformation of the brain and detection of associated intracranial primitive neuroectodermal tumor (trilateral retinoblastoma). Minimum requirements for pretreatment diagnostic evaluation of retinoblastoma or mimicking lesions are presented, based on consensus among members of the European Retinoblastoma Imaging Collaboration (ERIC). The most appropriate techniques for imaging in a child with leukocoria are reviewed. CT is no longer recommended. Implementation of a standardized MRI protocol for retinoblastoma in clinical practice may benefit children worldwide, especially those with hereditary retinoblastoma, since a decreased use of CT reduces the exposure to ionizing radiation.