ACROMEGALY AND A GIANT RETROPERITONEAL LIPOSARCOMA PRODUCING IGF-1.

objectiveLiposarcoma is the most common histotype of retroperitoneal sarcomas, representing up to 45% of all cases. We report a rare combination of acromegaly and liposarcoma in the same individual.

methodsLaboratory and imaging studies including an oral glucose tolerance test, measurements of growth hormone (GH) and insulin-like growth factor-1 (IGF-1), and a computed tomography scan were performed.

resultsThe patient was a 60-year-old male with a history of acromegaly diagnosed on the basis of elevated IGF-1 at 1,373 ng/mL (age-appropriate reference range is 87 to 225 ng/mL) and macroadenoma treated with transsphenoidal surgery. He presented 8 years later with a history of abdominal distension and weight loss. Physical examination was notable for a right-sided abdominal mass that was tense and non-fluctuant. Two years earlier, he had a post oral glucose tolerance test GH level <0.25 ng/mL and IGF-1 level of 256 ng/mL (age-appropriate reference range is 55 to 206 ng/mL). Pituitary magnetic resonance imaging reported a 3.7 × 2.0-mm left-sided parasagittal lesion. Computed tomography scan showed a 25.0 × 22.0 × 32.3-cm heterogeneous giant mass in the right abdomen corresponding to a liposarcoma causing displacement of kidney, liver, and bowel loops. The patient was treated with a complete en bloc resection of the liposarcoma with the right kidney (45 × 33 × 17 cm) and tumor (9,400 g). Immunohistochemical examination revealed positive IGF-1 and GH staining. The patient suffered postoperative gastrointestinal bleeding that resulted in hemorrhagic shock and died on the 29th postoperative day after a cardiorespiratory arrest.

conclusionAcromegalic patients are at increased risk of developing various types of neoplasms. This is the first documented coexistence of liposarcoma and history of acromegaly.