This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Anatomy
A 32 years lady present with shoulder tip pain and diagnosis is pan coast tumour and presents with miosis. Diagnosis is 
Select and explain. 
A. Horner syndrome, B. Thoracic outlet syndrome, C. Aberrant right subclan aery, D. Upper trunk of brachial plexus injury
A: Horner syndrome
Answer: A: Horner syndrome 
Explanation: Pan-coast tumor can cause compression of sympathetic ganglion resulting in Horner syndrome. These tumors are associated with Pancoast syndrome, characterized by pain, that may arise in shoulder / chest wall & characteristically radiates to ulnar surface of hand Features of Horner's syndrome: P - Ptosis M - Miosis E - Enophthalmos A- Anhidrosis L - Loss of ciliospinal reflex