The patient's presentation is consistent with TB pelvis with Tubo ovarian mass. The key points leading to this diagnosis include:
- Amenorrhea: Tuberculosis (TB) can affect the fallopian tubes and cause pelvic inflammatory disease, leading to menstrual abnormalities such as amenorrhea.
- Low-grade fever and weight loss: These systemic symptoms are classic signs of tuberculosis infection.
- Pain abdomen and generalized weakness: Both are common symptoms of pelvic TB.
- Pelvic mass on examination: Tubo-ovarian masses can form due to infection and inflammation caused by TB, mimicking other pathologies like tumors.
Taking these points into consideration, the combination of systemic symptoms, menstrual irregularities, and pelvic mass strongly suggest the presence of TB pelvic disease with associated tubo-ovarian mass. Other options like fibroid with degeneration, ectopic pregnancy, and granulosa cell tumor are less likely due to the absence of typical symptoms such as acute abdomen (for ectopic pregnancy) or estrogenic manifestations (for granulosa cell tumor).