In developed countries, few patients with retinoblastoma present with extraocular disease. Extraocular disease may be localized to the soft tissues surrounding the eye or to the optic nerve beyond the margin of resection. However, further extension may occur into the brain and meninges with subsequent seeding of the spinal fluid, as well as distant metastatic disease involving the lungs, bones, and bone marrow.
Almost all hypopharyngeal cancers are epithelial in origin, predominantly squamous cell (i.e., epidermoid) carcinomas (SCCs), and may be preceded by various precancerous lesions.[1,2] Rare types of hypopharyngeal carcinomas include the following:
Basaloid squamoid carcinomas.
Spindle-cell (i.e., sarcomatoid) carcinomas.
Nasopharyngeal-type undifferentiated carcinomas (i.e., lymphoepitheliomas).
Carcinomas of the minor salivary glands.
Orbital retinoblastoma occurs as a result of progression of the tumor through the emissary vessels and sclera. For this reason, transscleral disease is considered to be extraocular and should be treated as such. Orbital retinoblastoma is isolated in 60% to 70% of cases; lymphatic, hematogenous, and central nervous system (CNS) metastases occur in the remaining patients. Treatment should include systemic chemotherapy and radiation therapy; with this approach, 60% to 85% of patients can be cured. Since most recurrences occur in the CNS, regimens using drugs with well-documented CNS penetration are recommended. Different chemotherapy regimens have proven to be effective, including vincristine, cyclophosphamide, and doxorubicin and platinum- and epipodophyllotoxin-based regimens, or a combination of both. For patients with macroscopic orbital disease, it is recommended that surgery is delayed until response to chemotherapy has been obtained (usually two or three courses of treatment). Enucleation should then be performed and an additional four to six courses of chemotherapy administered. Local control should then be consolidated with orbital irradiation (4,000 cGy to 4,500 cGy). Using this approach, orbital exenteration is not indicated. Patients with isolated involvement of the optic nerve at the transsection level should also receive similar systemic treatment, and irradiation should include the entire orbit (3,600 cGy) with 1,000 cGy boost to the chiasm (total 4,600 cGy).
Intracranial dissemination occurs by direct extension through the optic nerve and its prognosis is dismal. Treatment for these patients should include platinum-based intensive systemic chemotherapy and CNS-directed therapy. Although intrathecal chemotherapy has been traditionally used, there is no preclinical or clinical evidence to support its use. Although the use of irradiation in these patients is controversial, responses have been observed with craniospinal irradiation, using 2,500 cGy to 3,500 cGy to the entire craniospinal axis and a boost (1,000 cGy) to sites of measurable disease. Therapeutic intensification with high-dose marrow-ablative chemotherapy and autologous hematopoietic progenitor cell rescue has been explored, but its role is not yet clear.[Level of evidence: 3iiA]
Trilateral retinoblastoma is usually associated with a pineal or, less commonly, a suprasellar lesion. In patients with the hereditary form of retinoblastoma, CNS disease is less likely the result of metastatic or regional spread than a primary intracranial focus, such as a pineal tumor. The prognosis for patients with trilateral retinoblastoma is very poor; most patients die of disseminated neuraxis disease in less than 9 months. While pineoblastomas occurring in older patients are sensitive to radiation therapy, current strategies are directed towards avoiding irradiation by using intensive chemotherapy followed by consolidation with myeloablative chemotherapy and autologous hematopoietic progenitor cell rescue, an approach similar to those being used in the treatment of brain tumors in infants.