Dalen-Fuch’s nodule are seen in: March 2013 (h)
**Core Concept**
Dalen-Fuchs nodules are a characteristic histopathological feature associated with uveitis, particularly in the context of sympathetic ophthalmia. They represent a collection of epithelioid cells and lymphocytes that accumulate between the retinal pigment epithelium and Bruch's membrane.
**Why the Correct Answer is Right**
In sympathetic ophthalmia, an inflammatory response is triggered after a penetrating eye injury or surgery, leading to the activation and infiltration of immune cells into the previously unaffected eye. The accumulation of epithelioid cells and lymphocytes between the retinal pigment epithelium and Bruch's membrane is a hallmark of this condition, forming Dalen-Fuchs nodules. This process is thought to be mediated by the release of various cytokines and chemokines that recruit and activate immune cells.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect, as Dalen-Fuchs nodules are not typically associated with sarcoidosis, which is characterized by non-caseating granulomas in various organs.
**Option B:** Incorrect, as choroidal melanoma is a type of primary intraocular malignancy that does not typically involve Dalen-Fuchs nodules.
**Option C:** Incorrect, as Fuchs heterochromic iridocyclitis is a form of chronic uveitis, but it is not specifically associated with Dalen-Fuchs nodules.
**Clinical Pearl / High-Yield Fact**
Dalen-Fuchs nodules are a key histopathological feature in the diagnosis of sympathetic ophthalmia, a rare but potentially devastating complication of eye trauma or surgery.
**Correct Answer: B. Sympathetic ophthalmia.**