<s>[INST] context: - Adenomyosis is a condition in which normal endometrial glands grow into the myometrium. Symptomatic disease primarily occurs in multiparous women over the age of 35 years, compared to endometriosis, in which onset is considerably younger. - Patients with adenomyosis complain of dysmenorrhea and menorrhagia, and the classical examination findings include a tender, symmetrically enlarged uterus without adnexal tenderness. - Although patients with endometriosis can have similar complaints, the physical examination of these patients more commonly reveals a fixed, retroveed uterus, adnexal tenderness and scarring, and tenderness along the uterosacral ligaments. - Uterine sarcoma is rare, and presents in older women with postmenopausal bleeding and nontender uterine enlargement. - As compared to fibroids, the 'Progressive' dysmenorrhea here is a classical presentation of adenomyosis. In adenomyosis, the uterine size is almost never more than 14 cms in size - Also, the fibroids are generally seen in nulliparous women and mostly the uterus is irregularly enlarged to varying sizes [/INST] question: A 39- year old woman , para 3 Live3, complains of severe, progressive secondary dysmenorrhea and menorrhagia. Pelvic examination demonstrates a tender, diffusely enlarged uterus of around 12 weeks pregnant size uterus, with no adnexal tenderness. Results of endometrial biopsy are normal. This patient most likely has:- | options: A: Endometriosis B: Endometritis C: Adenomyosis D: Uterine sarcoma | answer: C </s>