Final answer:
Severe acute scrotal pain, abnormal position of the testicle, and absence of the cremasteric reflex are key indicators of testicular torsion, which requires immediate medical attention.
Step-by-step explanation:
The assessment finding that would indicate testicular torsion in a 12-year-old boy presenting with scrotal pain would not be limited to hardened and tender epididymitis with edema and erythema of the scrotum. While these symptoms may be associated with epididymitis or orchitis, testicular torsion presents with an acute onset of severe scrotal pain, often with a high-riding testicle and a transverse lie, which refers to the horizontal position of the testis, as well as the absence of the cremasteric reflex (a reflexive retraction of the testis when the inner thigh is stroked).
The sudden and intense pain, along with the testicle's abnormal position and the urgency associated with the diagnosis, sets testicular torsion apart. Immediate medical attention is crucial for testicular torsion due to the risk of testicular loss if not treated promptly, which is not the case with epididymitis where the treatment often includes antibiotics, anti-inflammatory drugs, and painkillers.