Purtscher-Like Retinopathy Secondary to an Appendiceal Neuroendocrine Neoplasm Complicated by a Periappendiceal Abscess

Purtscher-like retinopathy (PLR) is a rare retinal microvasculopathy that is induced by non-traumatic systemic illnesses. We describe the case of a woman in her 70s who was diagnosed with PLR, ultimately linked to an appendiceal neuroendocrine neoplasm (ANEN) complicated by a periappendiceal abscess. The patient presented with sudden, unilateral, painless visual impairment. Initial examination revealed Purtscher flecken (PF) and cotton-wool spots (CWS) in the right eye, with corresponding hyperreflectivity and swelling of the inner retinal layers on optical coherence tomography (OCT). Systemic evaluation revealed elevated D-dimer levels: 547 ng/mL fibrinogen equivalent units (FEU) (normal <500 ng/mL FEU), and subsequent imaging identified a periappendiceal infiltrate. Laparoscopic appendectomy confirmed the presence of a well-differentiated grade 3 ANEN. Postoperative follow-up demonstrated regression of retinal findings and partial visual improvement (of BCVA from 1.4 logMAR to 0.5 logMAR in the affected eye). However, she presented a scotoma in the visual field of the right eye. The follow-up OCT showed localized inner retinal atrophy corresponding to prior ischemic changes. To our knowledge, this is the first reported case linking PLR to ANEN or appendicitis. This case highlights the importance of systemic evaluation in patients with PLR, particularly when typical aetiologies are excluded.