A 45 year old lady came with right lower abdominal pain radiating to right lower limb over 4 months. There were no other significant abdominal complaints. Patient did not have any contact with tuberculosis. Clinical examination was normal. Abdominopelvic ultrasonography showed 4 x 3 cm solid mass in right iliac fossa. Contrast enhanced CT of the abdomen (Fig. 1) showed homogeneous, vascular and well defined retroperitoneal solid mass overlying right iliacus muscle; suggestive of a benign neurogenic tumour. At laparotomy, a vascular tumour overlying the right femoral nerve was excised.
Histopathology (Fig. 2) showed atrophic germinal centre with vessel traversing through it: "lollypop appearance". The expanded mantle zone shows concentric rings of small lymphocytes: "onion skin appearance"- suggestive of hyaline vascular variant of Castleman disease.
All biochemical investigations and PET CT were normal. Patient is on follow up for 6 months and is doing well.