Hello Thanks for query . A lump (Node) with little pin in scrotal sac could be either a a staphylococcal infection of a hair follicle (Boil) or a Sebaceous cyst .However the precise diagnosis can be made only on clinical examination by a qualified General surgeon . The scrotal skin is rich in sebaceous glands and hence prone to get sebaceous cyst due to accumulation of sebum beneath the skin. Normally it fades away without treatment however need to be treated if increase in size or get infected. Take antibiotic like Doxicycline and Diclofenac twice daily for a week . If persist even after taking antibiotics consult General Surgeon for evaluation .It may need to get excised under local anesthesia. Dr.Patil.