Case 492 -- A woman in her 20s with an abdominal mass

Contributed by J. Manuel Zarandona, M.D., and Mamatha Chivukula, M.D.
Published on line in January 2007


A woman in her 20s presented to her primary care physician with a complaint of abdominal discomfort and distension for approximately one month. The patient reported constipation but denied nausea, vomiting, sharp abdominal pain, and rectal bleeding. Physical examination demonstrated diffuse abdominal tenderness and firmness without guarding. A transvaginal ultrasound revealed a large, complex, cystic and solid soft tissue mass within the pelvis, extending to 2 cm above the umbilicus. A CT scan of the abdomen and pelvis showed involvement of the right adnexa. The patient underwent a right salpingo-oophorectomy.


Alpha-Fetoprotein (AFP) 11023 ng/mL, CA 125 93 U/mL, CA 19-9 < 1.2 U/mL, CEA 2.1 ng/mL, hCG negative


The right salpingo-oophorectomy specimen consisted of an unremarkable fallopian tube and a 19 x 18 x 6 cm solid and cystic ovarian mass. The serosa was intact and smooth. Serial section of the mass demonstrated multiloculated cysts containing yellow, seromucinous fluid. The interior of the cyst wall was red-tan and smooth, with focal edema and intramural hemorrhage. The solid component was fleshy and tan-pink with yellow, rubbery-to-firm stellate areas. Separate from the main solid and cystic mass was a 6.5 cm area containing hair and friable, yellow material (Image 2).


Histologic sections of the smaller yellow, friable area showed epidermis with adnexal structures (Image 3).

Sections of the larger cystic and solid mass demonstrated branching, papillary structures containing thick basement membrane material and covered with cuboidal to low columnar cells (Images 4, 5 and 6). This arrangement was best seen in a cross-section of an individual papilla (Image 7). In addition to this pattern, microcystic spaces were prominent in other areas. Eosinophilic globules were present in a few sections (Image 8), and were found to be PAS-positive, diastase-resistant (Image 9).


Images of key positive immunohistochemical stains are shown above (Images 10 and 11). Stains for human chorionic gonadotropin (hCG), placental alkaline phosphatase (PLAP), and epithelial membrane antigen (EMA) were negative.


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