Luteinized Thecomas ("Thecomatosis") with Sclerosing Peritonitis (LTSP): Report of 2 Cases and Review of an Enigmatic Syndrome Associated with a Peritoneal Proliferation of Specialized (vimentin+/keratin+/CD34+) Submesothelial Fibroblasts

Abstract

Objective: To present the clinicopathologic features of two cases of luteinized thecomas with sclerosing peritonitis (LTSP), characterize the cellular proliferation in the sclerosing peritonitis (SP), and review the literature.

Methods: The clinical, laboratory, and imaging data, operative findings, and pathology materials were reviewed and summarized. Samples of the SP were stained with keratin AE1/AE3, vimentin, CD34, calretinin, smooth muscle actin, ER/PR, CD10 and desmin. A literature search was performed to identify cases of LTSP for comparison.

Results: A total of 43 cases of LTSP syndrome were identified. Frequent clinical features included ascites (74%), abdominal pain (35%), bowel obstruction (42%), and bilateral masses (84%). We isolated a distinct form of ovarian luteinized thecoma (thecomatosis) and peculiar sclerosing peritonitis (SP). IHC analysis shows a proliferation of specialized (vimentin+/keratin+/CD34+) submesothelial fibroblasts (SMF) with patchy expression of calretinin and hormone receptors.

Conclusion: LTSP syndrome is a rare entity presenting with abdominal pain, bowel obstruction, ascites, ovarian masses, and SP containing specialized (vimentin+/keratin+/CD34+) SMF. LTSP must be distinguished from abdominal cocoon, isolated SP, Meigs' syndrome, and peritoneal carcinomatosis. The importance of recognizing the diagnosis is stressed, as failure to manage this disease conservatively leads to significant morbidity and mortality. The SP and bowel obstruction may persist for months, even after resection of the tumours, resulting in extended medical therapy. Based on the immunophenotype of the peritoneal lesions, strategies to elucidate 'targeted' pharmacologic agents that could inhibit the proliferation of specialized (vimentin+/keratin+/CD34+) SMF may be of benefit.

Keywords: luteinizing thecoma; ovarian masses; sclerosing peritonitis; submesothelial fibroblasts.