Hello,
Gynecomastia is one of the presenting features in
testicular cancer but is not the sole symptom of
testicular cancer.
Testicular pain can also be due to injury, infection (Epididymitis or Orchitis) or inflammation, testicular torsion( most common in young men), excessive bicycle riding, hernia,varicocele or kidney or ureteric stones.
Lab investigations like complete blood examination, urine examination, ultrasound lower abdomen and sometimes a urethral swab will help in diagnosis.