Clinical Photo of The Week - Vol2, No9

This case was presented in the recent (Vol2No9) edition of otolaryngology news:
A 34-year old female presented with recurrent painful sublingual swelling of 3 years. The pain is occasionally felt on the adjoining lower gum. She has had several analgesia to no avail. She has no history of autoimmune disorders, trauma or drug allergy. Examination revealed the structure demonstrated in this picture.
Diagnosis: Infected ranula