<s>[INST] context: Endometrioma Another clinical based question with insufficient information to make any confirm diagnosis. At the best we can try to make the most probable diagnosis. Let's first see CA-125. CA-125 This is a non-specific tumor marker. Cut off level of CA-125 is < 35 U/ml. Ca 125 levels, as described above, can be raised in all the four options, so not very helpful in reaching a diagnosis. But if we weigh CA-125 level in terms of significance then it is least significant in tuberculosis as it is neither used for diagnosis nor for follow-up in tuberculosis. Palpable mass may be present in all the four conditions. Infeility is a feature of both endometriosis and tuberculosis. But for ovarian cancers infeility is a risk factor, not a feature or presenting symptom. Coming to Age: Patient is 35 yrs old. Age of 35 yrs ours endometrioma most. Peak incidence of invasive epithelial ovarian cancer (most common ovarian cancer) is at 56-60 yrs of age and for border line tumor average age is 46 yrs approximately (Novak). Patients with tuberculosis are in their twenties commonly, the maximum age incidence at diagnosis being 28 yrs. So on the basis of age and infeility, the most probable diagnosis would be endometrioma. [/INST] question: A 35 yr old woman presents with primary infeility & palpable pelvic mass. Her CA-125 level is 0 U/nil. Diagnosis is | options: A: Ovarian Ca B: Endometrioma C: Tuberculosis D: Borderline ovarian tumor | answer: B </s>