The tumor appearance and growth patterns will differ according to the physical nature of the invaded compartments. Solid tumors will adopt either a hemispherical endophytic or exophytic shape or a diffuse planar infiltration within the retinal tissue (diffuse infiltrative variant). Tumor spread into the viscous vitreous gel initially resembles dusty (loose cellular spread) or cloudy (dense cumulus-like spread) infiltrates, resulting from localized versus massive ILM/hyaloid disruptions, respectively (Fig. 13.2a–f). With time a subset of individual tumor cells will begin selective growth to form floating spheres with or without a whitish center. Under the effect of gravity, these vitreous tumors slowly migrate and tend to accumulate inferiorly at the ora serrata. Finally, tumor spread into the aqueous retrohyaloid or subretinal compartments is also associated with the formation of spheres, which differs from the vitreous ones by their ability to rapidly migrate according to gravitational stimuli and their tendency to accumulate inferiorly posterior to the vitreous base or under the ora serrata, respectively. In contrast to vitreous floating seeds, prehyaloid ones (Fig. 13.2i, j) are all located at the same level and tend to coalesce, similarly to ILM-anchored retrohyaloid seeds. Free cobblestone-like (pavimentous) seeds may form in the meniscus of liquid created by partial posterior hyaloid detachment (Fig. 13.2g, h). Finally, a large hyaloid disruption at the tumor base can be followed by a massive transfer of tumor material into the retrohyaloid space creating a position-dependent circular level (Fig. 13.2k–n). When the tumor invades the aqueous fluid of the anterior segment, the semiologic features can be divided into free-floating spheres or tumor cells possibly forming a pseudo-hypopyon or tumor attached to the iris (spheres) and corneal endothelium (pavimentous growth).