An extremely rare case of metastatic retinoblastoma of parotids presenting as a massive swelling in a child

Retinoblastoma (Rb) is a common childhood malignancy but bilateral Rb with metastasis to parotids is very uncommon. To the best of our knowledge, bilateral Rb metastasizing to parotids is very rare and this is the fifth such case reported in world literature till date in a 2-year-old male child who underwent exenteration of left eye for bilateral Rb and later developed recurrent metastasis to left parotid requiring parotidectomy. A year later he presented again with swelling left parotid region extending from occipital region reaching upto left anterior chest wall with intra-cranial extension on magnetic resonance imaging. Histopathological examination of the parotid swelling and immunohistochemistry showed metastasis from Rb. He was treated with chemotherapy followed by radiotherapy to local site and brain to which he responded well. Presently on regular follow up without any signs of locoregional and distal metastasis. Till date different types of primary parotid tumors have been reported in literature but a metastatic parotid tumor is extremely rare and therefore this case is being reported to highlight the extreme rarity, the diagnostic and therapeutic challenges, the highly aggressive nature and overall dismal prognosis of this disease entity.