🟢 Retinal astrocytic hamartomas (RAH) are benign retinal tumors composed of glial cells. They are typically encountered as an asymptomatic lesion in patients with tuberous sclerosis complex (TSC); however, may be isolated tumors or found in association with other ocular or systemic disease. Most RAH are thought to be congenital, but may not become clinically apparent until later in life. 🟢 RAH are diagnosed clinically based on characteristic ophthalmoscopic appearance. Ancillary testing may be of value in establishing a diagnosis in patients with atypical appearing lesions or those without tuberous sclerosis. Biopsy is rarely required and not typically recommended for RAH. Fine-needle aspiration for cytopathology can however be performed in atypical cases.Cytology demonstrates spindle cells, and immunohistochemistry staining is positive for glial cells (glial-fibrillary acidic protein stain). TSC is a clinical diagnosis, but genetic testing for TSC1 and TSC2 mutations is available. 🟢 Classically, three morphological subtypes of RAH have been described: 👉 Type 1 (most common): relatively flat, smooth, semitransparent, grey-white lesions without calcification 👉 Type 2: raised, multinodular (‘mulberry-like’), opaque, calcified lesions 👉Type 3: transitional lesion with features of Type 1 and Type 2 Lesions typically remain stable with age, and do not evolve between types. 🟢 TSC patients may require treatment of subependymal giant cell astrocytomas with mTOR inhibitors (eg everolimus, sirolimus). mTOR inhibitors have been shown to cause regression of RAH, and have been used for aggressive ocular disease in a child. 🔸References: https://eyewiki.org/Retinal_Astrocytic_Hamartoma 🔸Images: @dr._ophthalmologist_ @retinaconsultantstexas @dra.lucia_falla @nyeye @istanbulretina @retina.review @interesting_retinal_cases @retina.vitreo @aaoeye @retinacorneaclub @retof