Question

A 35 year old nullipara female presented with dull aching pain with exacerbation during menstrual cycle. Usg reveals a heterogenous mass in right adnexa. Mri reveals a 4 x 5 cm T1 hyperintense mass with no suppression on fat started images. T2 weighted images show low signal with Dark shading. Diagnosis?

• A. Dermoid cyst
• B. Endometrioma
• C. Ovarian cancer
• D. Para Ovarian Cyst

Hint:

T1 bright that does NOT suppress on fat sat = blood, not fat; add cyclical pain and 'T2 shading' and you have a chocolate cyst.

Answer 1

The Correct Option is B

Step 1: Read the clinical picture. A 35-year-old woman has cyclical (menstrual-related) pelvic pain plus an adnexal mass. Cyclical pain that worsens with menses strongly suggests an endometriotic lesion, because ectopic endometrial tissue bleeds with each cycle.

Step 2: Analyse the MRI signal - this is the key. The mass is T1 hyperintense (bright on T1). T1 brightness is caused by blood/methaemoglobin or fat. To tell them apart we use fat suppression: here the mass shows no suppression on fat-saturated images, meaning the T1 brightness is from blood (haemorrhage), NOT fat.

Step 3: The 'T2 shading' sign. On T2-weighted images the mass shows low signal with dark shading. "T2 shading" - loss/dimming of the normally bright T2 fluid signal due to chronic blood products (high protein/iron from repeated cyclical haemorrhage) - is the classic MRI hallmark of an endometrioma (chocolate cyst).

Step 4: Why option B (Endometrioma) is correct. T1 bright + does NOT suppress with fat sat (blood, not fat) + T2 shading + cyclical pain = endometrioma.

Step 5: Why the distractors are wrong. (A) Dermoid cyst (mature teratoma) is also T1 bright, but it DOES suppress on fat-saturated images because its brightness is from fat - the opposite of this case. (C) Ovarian cancer typically shows solid enhancing/papillary components, septations and is not characterised by uniform T1-bright/T2-shading haemorrhagic content; the benign cyclical history also argues against it. (D) Para-ovarian cyst is a simple cyst (T1 dark, T2 bright, follows fluid) and would not be T1 hyperintense or show shading.

Final Answer: Option B - Endometrioma.