Peritoneal Sarcomatosis Versus Peritoneal Carcinomatosis: Imaging Findings at MDCT

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1 Gastrointestinal Imaging Pictorial Essay Oei et al. MDCT of Peritoneal Sarcomatosis and Carcinomatosis Gastrointestinal Imaging Pictorial Essay Downloaded from by on 01/12/18 from IP address Copyright RRS. For personal use only; all rights reserved Tamara N. Oei 1 Jyothi P. Jagannathan 2 Nikhil Ramaiya 2 Pablo R. Ros 3 Oei TN, Jagannathan JP, Ramaiya N, Ros PR Keywords: oncology, peritoneal carcinomatosis, peritoneal sarcomatosis, sarcoma DOI: /JR Received November 2, 2009; accepted after revision February 21, Department of Radiology righam and Women s Hospital, Harvard Medical School, Mellins Library, 75 Francis St., oston, M ddress correspondence to T. N. Oei (toei@partners.org). 2 Department of Radiology, Dana Farber Cancer Institute, Harvard Medical School, oston, M. 3 Department of Radiology, Case Western Reserve University, Cleveland, OH. WE This is a Web exclusive article. JR 2010; 195:W229 W X/10/1953 W229 merican Roentgen Ray Society Peritoneal Sarcomatosis Versus Peritoneal Carcinomatosis: Imaging Findings at MDCT OJECTIVE. Peritoneal sarcomatosis is an entity analogous to the better known peritoneal carcinomatosis. The purpose of this article is to discuss the imaging findings of peritoneal sarcomatosis versus peritoneal carcinomatosis. CONCLUSION. Sarcomatosis is most commonly seen in gastrointestinal stromal tumor, liposarcoma, and leiomyosarcoma. few distinguishing features of peritoneal sarcomatosis include heterogeneous bulky masses, hypervascularity with or without hemoperitoneum, and variable presence of ascites. P eritoneal sarcomatosis, defined as disseminated intraperitoneal spread of sarcoma in the absence of significant extraabdominal sites of disease, is a rare entity recently described in the oncology literature [1, 2]. Soft-tissue sarcomas comprise 0.7% of all cancers and frequently metastasize to the lung, followed by bone and liver [3]. Sarcomatosis may arise from recurrent intraabdominal sarcomas or may be metastatic from extremity sarcomas. The most frequent tumors that give rise to peritoneal sarcomatosis are gastrointestinal stromal tumors (GISTs), liposarcomas, and leiomyosarcomas. Peritoneal sarcomatosis belongs to peritoneal surface malignancies, along with carcinomatosis and lymphomatosis [4]. The most wellknown and commonly encountered peritoneal surface malignancy is peritoneal carcinomatosis, the majority arising from gastric or ovarian primary malignancies [5]. ll peritoneal surface malignancies share similar radiologic features, with seeding of soft-tissue implants along the peritoneum and omentum, rendering differentiation of sarcomatosis from other peritoneal surface malignancies difficult solely by imaging. However, unlike carcinomatosis, the presence of ascites is variable in sarcomatosis [6]. Peritoneal implants from sarcomas are more often spherical and deforming, often vascular, and associated with minimal ascites, whereas carcinomatosis implants tend to be flat or ovoid and conform to the adjacent structures. owel obstruction and hydronephrosis are less frequently seen with sarcomatosis. To our knowledge, the findings in peritoneal sarcomatosis have not been previously reported in the radiologic literature. The purpose of this article is to review the types of soft-tissue sarcomas manifesting as peritoneal sarcomatosis and describe their imaging features. Gastrointestinal Stromal Tumor GIST has emerged in recent years as one of the most common soft-tissue sarcomas in the United States, distinguished from other gastrointestinal mesenchymal tumors by expression of KIT protein (CD117), a mechanism that is specifically targeted by imatinib, a tyrosine kinase inhibitor [7]. lthough GIST can arise anywhere in the gastrointestinal tract, it most commonly originates in the stomach and small bowel. GIST primarily metastasizes to the liver (65%) and peritoneum (21 45%) [7, 8] (Figs. 1 3). side from the rare epithelial subtype, GIST does not metastasize to lymph nodes [7]. Peritoneal tumor burden in GIST is most often seen as large discrete masses that are often necrotic with heterogeneous enhancement (Figs. 1 and 2) and less commonly as diffuse hypervascular omental and peritoneal caking [7] (Fig. 3). Necrosis within the masses may lead to enteric fistulization, spontaneously or during treatment [9]. ecause of hypervascularity, patients with GIST may develop gastrointestinal bleeding and hemoperitoneum [9]. scites is variable and its presence alone may not imply peritoneal disease because ascites is often seen during therapy with tyrosine kinase inhibitors [8] (Figs. 2 and 3). JR:195, September 2010 W229

2 Oei et al. Downloaded from by on 01/12/18 from IP address Copyright RRS. For personal use only; all rights reserved Liposarcoma Liposarcoma accounts for 20% of all softtissue sarcomas in adults and is the most common retroperitoneal sarcoma [10, 11]. Five histologic subtypes of liposarcoma in order of increasing malignant behavior are well differentiated, dedifferentiated, myxoid, round cell, and pleomorphic. Most retroperitoneal liposarcomas are well differentiated and dedifferentiated subtypes [10]. The amount of macroscopic fat within the tumor decreases with more aggressive histologic subtypes. Myxoid liposarcoma is a distinct subtype characterized by homogeneous lowdensity masses with a propensity for spread to the peritoneum, mesentery, retroperitoneum, spine, and paraspinal soft tissues [12]. Retroperitoneal liposarcoma is known to recur frequently with multiple intraabdominal masses after resection [13] (Figs. 4 and 5). The peritoneal masses are often heterogeneous in density, with variable proportions of fat and soft tissue and with occasional calcification (Fig. 4). The soft-tissue component tends to show mild to moderate enhancement (Fig. 5). scites is typically not seen. lthough disseminated peritoneal liposarcoma is not responsive to conventional chemotherapy, its clinical course tends to be indolent [11]. Surgery is reserved for rapidly growing masses and intestinal obstruction by tumor [10]. Leiomyosarcoma Leiomyosarcoma is a malignant neoplasm of smooth muscle origin arising most commonly from the genitourinary tract, usually the uterus, retroperitoneum, and gastrointestinal tract [2] (Figs. 6 and 7). Primary involvement of the peritoneum by leiomyosarcoma occurs in rare instances, and late recurrences have been reported [5]. Peritoneal spread may be seen as diffuse peritoneal thickening or focal masses. Tumor implants are often large, heterogeneous, and intensely enhancing and may show calcification. scites is not a dominant finding. Complications include bowel obstruction (Fig. 7) or hemoperitoneum. Malignant Peritoneal Mesothelioma Malignant mesothelioma, a neoplastic process of mesothelial cell origin, is associated with asbestos exposure, typically involving the pleura but in 6 10% of cases involving primarily the peritoneum [14]. The sarcomatous subtype is associated with a worse prognosis than the epithelial and mixed subtypes. Pleural calcifications from asbestos exposure may be seen (Fig. 8). The imaging appearance of peritoneal mesothelioma varies from diffuse peritoneal soft-tissue thickening to more focal peritoneal masses with or without ascites [14 16] (Figs. 8 and 9). Desmoplastic Small Round Cell Tumor Desmoplastic small round cell tumor is a rare aggressive malignancy that occurs in adolescents and young adults, mostly male, and carries a poor prognosis [14, 17]. This entity is characterized by single or multiple peritoneal masses usually beginning in the omentum or paravesical region and spreading to the entire abdominal cavity [17] (Fig. 10). One study showed that a small to moderate amount of ascites was present in 56% of patients, and hepatic metastases were present in 33% [17]. Distinguishing Peritoneal Sarcomatosis From Other Uncommon Sarcomas Other sarcomas that rarely give rise to a similar pattern of peritoneal dissemination include clear cell sarcoma, rhabdomyosarcoma, alveolar soft part sarcoma, solitary fibrous tumor, and myxoid chondrosarcoma. Figure 11 shows an example of clear cell sarcoma, also known as malignant melanoma of soft parts, a rare highly aggressive soft-tissue sarcoma arising from the deep soft tissues of the extremities in young adults that has been shown to produce peritoneal sarcomatosis in a few cases [18 20]. Rhabdomyosarcoma, the most common soft-tissue sarcoma in the pediatric population [3], usually occurs in the head and neck, genitourinary tract, and extremities [21, 22]. Rarely, peritoneal dissemination of rhabdomyosarcoma occurs, visualized as heterogeneous soft-tissue implants in the abdomen (Fig. 12). lveolar soft part sarcoma is a slow-growing tumor of young adults frequently arising from the deep tissues of the lower extremities [23]. lthough, typically, alveolar soft part sarcoma metastasizes to the lung, brain, and bone, unusual locations such as the peritoneum are seen (Fig. 13). On imaging, the primary tumor and metastases appear hypervascular, with prominent peripheral flow voids at MRI [23]. Solitary fibrous tumor is a rare tumor most commonly arising from the pleura, but it has been reported in various extrathoracic sites, including the orbit, paranasal sinuses, retroperitoneum, and peritoneum (Fig. 14). Most solitary fibrous tumors are benign; however, approximately 10% are malignant and may show peritoneal dissemination [24]. Rarely, extraskeletal myxoid chondrosarcoma may metastasize to the peritoneum with low-density soft-tissue masses that reflect their myxoid substance (Fig. 15). Conclusion Peritoneal sarcomatosis is a rare entity whereby sarcoma spreads throughout the peritoneal cavity in a manner analogous to the better known peritoneal carcinomatosis. The most common types of sarcoma to produce this pattern of disease are GIST, liposarcomas, and leiomyosarcomas. The appearance of peritoneal sarcomatosis may show overlap with carcinomatosis, although bulky heterogeneous masses, hypervascularity, variable ascites, and hemoperitoneum are more characteristic of sarcomatosis. References 1. aratti D, Kusamura S, Deraco M. The Fifth International Workshop on Peritoneal Surface Malignancy (Milan, Italy, December 4-6, 2006): methodology of disease-specific consensus. J Surg Oncol 2008; 98: Rossi CR, Casali P, Kusamura S, et al. The consensus statement on the locoregional treatment of abdominal sarcomatosis. J Surg Oncol 2008; 98: National Cancer Institute, U.S. National Institutes of Health. Surveillance epidemiology and end results. seer.cancer.gov. Published ccessed September 20, Kim Y, Cho O, Song S, Lee H, Rhim H, Koh. Peritoneal lymphomatosis. bdom Imaging 1998; 23: Pickhardt PJ, halla S. Primary neoplasms of peritoneal and subperitoneal origin: CT findings. RadioGraphics 2005; 25: ilimoria MM, Holtz DJ, Mirza NQ, et al. Tumor volume as a prognostic factor for sarcomatosis. Cancer 2002; 94: Katz SC, DeMatteo RP. Gastrointestinal stromal tumors and leiomyosarcoma. J Surg Oncol 2008; 97: urkill GJ, adran M, Thomas JM. Malignant gastrointestinal stromal tumor: distribution, imaging features, and pattern of metastatic spread. Radiology 2003; 226: King DM. The radiology of gastrointestinal stromal tumors (GIST). Cancer Imaging 2005; 5: Dalal KM, ntonescu CR, Singer S. Diagnosis and management of lipomatous tumors. J Surg Oncol 2008; 97: Kim EY, Kim SJ, Choi D, et al. Recurrence of W230 JR:195, September 2010

3 MDCT of Peritoneal Sarcomatosis and Carcinomatosis retroperitoneal liposarcoma: imaging findings and diological manifestations. bdominal Imaging JM. Clear cell sarcoma of the abdominal wall growth rates at follow-up CT. JR 2008; 191:1841 [Epub 2009 Mar 25] with peritoneal sarcomatosis: CT features. Eur Ros PR, Yusehok TJ, uck JL, et al. Peritoneal Radiol 1999; 9: Estourgie SH, Nielsen GP, Ott MJ. Metastatic pat- mesothelioma: radiologic appearances correlated 21. Crist W, Gehan E, Ragab H, et al. The Third terns of extremity myxoid liposarcoma and their with histology. cta Radiol 1991; 32: Intergroup Rhabdomyosarcoma Study. J Clin On- outcome. J Surg Oncol 2002; 80: Pickhardt PJ, Fisher J, alfe DM, et al. Desmo- col 1995; 13: Downloaded from by on 01/12/18 from IP address Copyright RRS. For personal use only; all rights reserved 13. Jaques DP, Coit DG, Hajdu SI, rennan MF. Management of primary and recurrent soft-tissue sarcoma of the retroperitoneum. nn Surg 1990; 212: Levy D, rnaiz J, Shaw J, et al. From the archives of FIP: primary peritoneal tumors imaging features with pathologic correlation. Radio- Graphics 2008; 28: Souza FF, Jagannathan J, Ramayia N, et al. Recurrent malignant peritoneal mesothelioma: ra- Fig year-old man with gastrointestinal stromal tumor. Coronal contrast-enhanced CT image shows bulky peritoneal and bilateral paratesticular masses. Metastatic lesion is also seen in liver (arrow). No ascites is present. plastic small round cell tumor of the abdomen: radiologic histopathologic correlation. Radiology 1999; 210: Malchau SS, Hayden J, Hornicek F, et al. Clear cell sarcoma of soft tissues. J Surg Oncol 2007; 95: Ohba Y, Suzuki H, Hiraga H, et al. Melanotic peritoneal sarcomatosis originating from clear cell sarcoma. Pathol Int 1999; 49: Sabaté JM, Torrubia FS, Villaneuva, Monill Fig year-old woman with gastrointestinal stromal tumor. Coronal contrast-enhanced CT image shows multiple necrotic peritoneal masses (arrows). Massive ascites is secondary to fluid retention from imatinib therapy. 22. Maurer HM, Gehan E, eltangady M, et al. The Intergroup Rhabdomyosarcoma Study: II. Cancer 1993; 71: Dickerson TD, Owen J. lveolar soft part sarcoma. ppl Radiol 2008; 37: Vallat-Decouvelaere V, Dry SM, Fletcher CD. typical and malignant solitary fibrous tumors in extrathoracic locations: evidence of their comparability to intra-thoracic tumors. m J Surg Pathol 1998; 22: Fig year-old woman with gastrointestinal stromal tumor. Coronal contrast-enhanced CT image shows diffuse peritoneal caking limiting distinction of bowel. Few cystic masses (arrows) are also noted. scites is minimal. Fig year-old man with liposarcoma. and, xial () and coronal () contrast-enhanced CT images show multiple smooth round masses in peritoneum with soft-tissue attenuation and fat density and some with coarse calcification (arrows) representing various degrees of dedifferentiation. No ascites is present. JR:195, September 2010 W231

4 Oei et al. Fig year-old man with liposarcoma. C, xial ( and ) and coronal (C) contrast-enhanced CT images show multiple masses of variable attenuation in peritoneum and moderate ascites. There is nodular thickening of omentum (arrow, ). Peritoneal surface is thickened and hyperenhancing (arrow, C). Downloaded from by on 01/12/18 from IP address Copyright RRS. For personal use only; all rights reserved Fig year-old man with leiomyosarcoma. C, xial ( and ) and coronal (C) contrast-enhanced CT images reveal studding of peritoneal cavity with multiple heterogeneous masses. Solid and cystic implants are seen along liver (black arrows, and C) and spleen. Layering hemorrhage in multiple cystic masses is noted anterior to spleen and in pelvis (white arrows, and ). scites is minimal. Fig year-old man with leiomyosarcoma. and, xial () and coronal () contrast-enhanced CT images reveal large volume ascites and dominant cystic and solid mass with ill-defined borders encasing proximal ileum and causing partial smallbowel obstruction (thick arrows) with dilated loops of bowel (thin arrow, ) proximal to obstruction. C C W232 JR:195, September 2010

5 MDCT of Peritoneal Sarcomatosis and Carcinomatosis Downloaded from by on 01/12/18 from IP address Copyright RRS. For personal use only; all rights reserved Fig year-old man with malignant peritoneal mesothelioma. Coronal CT shows multiple omental nodules (thick arrow), serosal implants thickening unopacified loops of bowel (arrowheads), and minimal ascites (curved arrows). Calcified pleural plaques are consistent with prior asbestos exposure (thin arrow). C Fig year-old woman with malignant peritoneal mesothelioma. and, xial () and reformatted coronal () contrast-enhanced CT images show omental mass (white arrows), diffuse soft-tissue infiltration along leaves of mesentery (black arrows), encasement of bowel loops (asterisks), and moderate ascites. D Fig year-old man with desmoplastic small cell round tumor. D, xial () and reformatted coronal () contrastenhanced CT images show lobular paravesicular mass (arrows, and ). xial (C) and reformatted coronal (D) contrast-enhanced CT images after initial treatment show tumor recurrence with multiple peritoneal implants around liver and spleen (arrowheads, C) and extensive tumor deposits in porta hepatis (curved arrow, D) and in right subphrenic space (thick arrow, D). No ascites is present. JR:195, September 2010 W233

6 Oei et al. Fig year-old man with clear cell sarcoma. and, xial contrast-enhanced CT images show diffuse hepatic metastases (), soft-tissue implants along peritoneal surfaces in pelvis (arrows, ), and moderate amount of ascites (). Downloaded from by on 01/12/18 from IP address Copyright RRS. For personal use only; all rights reserved Fig year-old man with rhabdomyosarcoma. and, xial contrast-enhanced CT images show soft-tissue implants within peritoneal cavity. Dilated, contrast-filled loops of small bowel (arrowheads, ) lead down to obstructed segment, narrowed by metastatic serosal deposits (arrows, ). Notice paucity of ascites. Fig year-old man with alveolar soft part sarcoma. and, xial contrast-enhanced CT images reveal multiple hypervascular pulmonary metastases (). Rim enhancing necrotic mass is seen in gastrosplenic ligament (arrow, ). Fig year-old woman with malignant solitary fibrous tumor. Coronal contrast-enhanced CT image shows bulky intraperitoneal masses (arrows) with paucity of ascites. W234 JR:195, September 2010

7 MDCT of Peritoneal Sarcomatosis and Carcinomatosis Fig year-old woman with myxoid chondrosarcoma. and, xial contrast-enhanced CT images show multiple low-attenuation masses in abdomen (arrowheads, ) and pulmonary metastasis in right lower lobe (arrow). scites is absent. Right lower rib lesion () and right iliac osteochondroma () are also seen. Downloaded from by on 01/12/18 from IP address Copyright RRS. For personal use only; all rights reserved FOR YOUR INFORMTION Unique customized medical search engine service from RRS! RRS GoldMiner is a keyword- and concept-driven search engine that provides instant access to radiologic images published in peer-reviewed journals. For more information, visit JR:195, September 2010 W235