a 2-year - old female child presented with rapid onset massive proptosis of the left eye with difficulty to close and move the eye . on examination , she had proptosis of 31 mm ( exophthalmometry of right eye  11 mm ) with lid edema and ciliary congestion [ fig congested vessels were noted on the upper lid . there was a total restriction of extraocular movements . there was a 1 cm  1 cm firm scleral nodule 3 mm temporal to limbus with bluish discoloration and hemorrhage in it [ fig . 2 ] . the anterior chamber had exudate and hyphema precluding visualization of the posterior segment . the corneal diameters of the right and left eye were 11 and 12 mm , respectively . the measured intraocular pressure was 17.3 mmhg in the right eye and unrecordably high in the left eye ( schiotz tonometry ) . proptosis with ciliary congestion and chemosis computed tomography of orbit and brain revealed 4 cm  3 cm  2.5 cm heterogenous mass with intra- and extra - ocular component filling the left orbit [ fig . 3 ] . there were areas of coarse calcification . the optic nerve was encased within the mass with perineural spread up to optic chiasma . computed tomography scan showing orbital mass with intraocular extension and calcification histopathological examination of incisional biopsy of orbital mass showed small round tumor cells in sheets separated by incomplete fibrous septa under low power . examination at higher magnification revealed round to polygonal cells with high nucleocytoplasmic ratio , palisading of nuclei , and delicate cytoplasmic processes . few foci with central fibrillary material with tumor cells around giving vague appearance of rosettes ( homer wright ) were seen [ fig . 4 ] . positive for neuron specific enolase and chromogranin systemic evaluation for primary site was done . ultrasound abdomen and the child had hemoglobin of 12 g , total leukocyte count of 5400 , and platelet count of 141,000 . she was treated with three cycles of chemotherapy comprising vincristine 1.4 mg / m , adriamycin 60 mg / m , and cyclophosphamide 600 mg / m . after completion of three cycles , the tumor melted completely , and the child was systemically well [ fig . based on a clinical presentation on the day 1 , this child was initially treated as a case of orbital cellulitis . later , it was mistaken for retinoblastoma with orbital extension based on the age of the child and the presence of intraocular calcification . neuroblastoma was not considered initially as there was no abdominal mass , and primary orbital neuroblastoma has never been reported to have intraocular extension . other solid tumors that metastasize to orbit are wilms tumor , ewings sarcoma , and testicular sarcoma . differentiated neuroblastoma is made of mature ganglion cells , schwann cells , and nerve bundles . immunohistochemistry plays an important role in differentiating neuroblastoma from other small round cell tumors such as retinoblastoma , rhabdomyosarcoma , and lymphoma . tumors cells are stained for neuronal markers such as neuron specific enolase , chromogranin , and synaptophysin which aids in the diagnosis of neuroblastoma . delayed diagnosis in a rapidly growing tumor would have led to intraocular extension of the tumor . reports of tumor cells being found in the choroidal vasculature in histological section without obvious intraocular extension of solid tumors have been reported . the remote possibility of the tumor arising within the choroid and spreading out into the orbit may be considered . bilateral choroidal neuroblastomas , diagnosed on histopathological examination , to be primary rather than metastatic , have been described . the diagnosis of neuroblastoma is often delayed due to its varying and nonspecific presenting symptoms .
neuroblastoma is an undifferentiated malignancy of primitive neuroblasts . 
 neuroblastoma is among the most common solid tumors of childhood . 
 orbital neuroblastoma is typically a metastatic tumor . in this case report , we describe a 2-year - old child with a rapidly progressing orbital tumor . 
 computed tomography revealed an orbital mass lesion with extraocular and intraocular components . 
 an incisional biopsy was done , and a histopathological examination showed features suggestive of neuroblastoma . 
 systemic workup including ultrasonography of the abdomen , chest roentgenogram , whole body computed tomography , and bone scintigraphy showed no evidence of systemic involvement . 
 the diagnosis of primary orbital neuroblastoma was made , and the child was subjected to chemotherapy followed by rapid melting of the tumor . 
 neuroblastoma should be considered in the differential diagnosis of childhood orbital tumors .