CT in diagnosis of primary and recurrent retroperitoneal liposarcomas.

Transcription

1 CT in diagnosis of primary and recurrent retroperitoneal liposarcomas. Poster No.: C-0162 Congress: ECR 2016 Type: Scientific Exhibit Authors: A. Meldo 1, I. A. Burovik 2 ; 1 Saint-Petersburg/RU, 2 S-Peterburg/RU Keywords: Oncology, CT, Diagnostic procedure, Neoplasia DOI: /ecr2016/C-0162 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 11

2 Aims and objectives According to the international classification of sarcomas retroperitoneal tumors are included in the group of soft tissue tumors (1). The planning of surgical treatment primarily determined by the tumor localization# This fact gives the opportunity to create a classification of retroperitoneal tumors based on their histological structure and localization. Thus organic tumors of the retroperitoneal space or the abdominal cavity have been excluded (2). Liposarcoma is the most common mesenchymal malignant tumor (3, 4). Currently the problem of diagnostics and treatment of retroperitoneal tumors has received considerable attention, surgical method of treatment is the main (5-9). The problem of early detection of this pathology is still unresolved due to a long asymptomatic period, the nonspecific first manifestations (1). There are several histological types of liposarcoma, with own CT patterns. Welldifferentiated liposarcoma has adipose tissue density, myxoid liposarcoma's density is equal to water. Pleomorphic and dedifferentiated histological types have "soft tissue" density (10). Calcifications are extremely rare (11). Knowledge of these features can be useful in the diagnostics of liposarcoma and planning adequate surgery. Liposarcomas recur in 80% cases. Differentiation of recurrent tumor cells often is lower than of prymary (4,5). CT is the main method of diagnostics of retroperitoneal liposarcomas (10-12). PURPOSE OF THE STUDY 1. To systematize and clarify CT-semiotics of primary and recurrent retroperitoneal liposarcoma. 2. To determine the informativity of CT in the diagnosis of retroperitoneal liposarcoma. 3. To evaluate CT patterns of recurrent liposarcomas in the planning of surgical operations. Methods and materials If retroperitoneal tumor was suspected contrast enhanced CT was performed. Liposarcomas dominated (Fig. 1). Page 2 of 11

3 We include in this study 36 cases of retroperitoneal liposarcomas in 33 patients. There were 20 primary and 16 recurrent cases. Women were 23 (69,7%), men were 10 (30,3%). The age of patients ranged from 20 to 79 years old with a prevalence of the 7 decade of life (Fig. 2). The average age was 55.5 years #=14,2 years old. Quantity, size, density, vessel and organ invasion of tumor nodes were determined. Images for this section: Fig. 1: The distribution of mesenchymal tumors Page 3 of 11

4 Fig. 2: The age distribution of patients with retroperitoneal liposarcomas Page 4 of 11

5 Results Clinical symptoms in most cases (75,0%) were absent (Fig. 3 ), in general tumors were detected accidentally during routine surveys about other pathology. Primary liposarcomas had a large size (Me = 11,5 [8,0; 16,0] cm). In 15 patients (75%) the tumor consisted of a single node, in 5 (25%) had a multinodular structure. Primary liposarcomas were characterized by wide density range. So the minimum density varied from -143 HU to +36 HU (Me = -35 [-94,0; +18] HU), the maximum density ranged from -15 HU to +50 HU (Me = 29 [19,0 mm; 34,0] HU), the density gradient was from -143 to +41HU (Me = -30,5 [-101; +24,3] HU). The most of tumor nodes (65,0%) did not change density in post contrast (portal) phase, except soft-tissue density components. The post contrast phase density of the primary liposarcomas ranged from -143HU to +160HU (Me = 23,0 [-63,0; +50,0] HU). Recurrence-free period after the first operation was 4-10 years (mean 32.8 months), the time between the first and second relapse was significantly short (mean 19.2 months). The third relapse in one patient was 6 months after the last operation. There was a statistically significant difference of primary and recurrent liposarcoma densities in portal vein phase (p < 0.05). Analysis of post contrast density distributions in subgroups of primary and recurrent liposarcomas showed that primary were characterized by an asymmetrical towards negative values of the Hounsfield scale (half of the observations was in the range from -143 to +20 HU, and the other half was in the interval from +20 to +41HU). Recurrences were characterized by a symmetrical distribution with a slight asymmetry toward positive values. The maximum density more than +60HU had only recurrent liposarcomas (Fig. 4). 9 patients with recurrent liposarcomas had multinodular tumor, with different CT patterns of nodes. We marked abnormal tissue areas in CT scans before operations. After surgery all marked parts were sent for histological and immunohistochemical studies. The parts of not demarcated compact adipose tissue also interpreted as a tumor, which was confirmed by morphological examination (Fig. 5, 6). Minimal size of determined recurrent liposarcoma was 5mm (Fig. 7). Informativity contents of CT are: sensitivity = 100% specificity = 78.9% accuracy = 95.4% Page 5 of 11

6 Images for this section: Fig. 3: Clinical symptoms of retroperitoneal liposarcomas Page 6 of 11

7 Fig. 4: Comparing of density characteristics of primary and recurrent liposarcomas in portal phase. Page 7 of 11

8 Fig. 5: Recurrence of retroperitoneal liposarcoma, combined nodes with different differentiation of cells. Abnormal tissue areas are marked on CT scans. The results of morphological study: # 1 - dedifferentiated liposarcoma, # 2 - myxoid liposarcoma, # 3, # 4 - well-differentiated liposarcoma. Page 8 of 11

9 Fig. 6: Recurrence of retroperitoneal liposarcoma with different structure of nodes. # 1, # 2 - myxoid liposarcoma, # 3, # 4 - well-differentiated liposarcoma. Fig. 7: Patient 61 years old. A - 7 years after excision of primary retroperitoneal liposarcoma, there isn't recurrence; B - 8 years after excision, there is recurrence 5 mm (arrow); C - 9 years after excision, the recurrent node has increased to 12 mm (arrow) Page 9 of 11

10 Conclusion Retroperitoneal liposarcomas don`t have specific clinical symptoms. They are occurred in persons older than 50 years. Women suffer twice as often than men. Features of liposarcoma are heterogeneous structure and wide density range. The recurrence of the liposarcoma can include areas with different cell grade, resulting in the CT patterns. Well-differentiated recurrent liposarcoma can look like not demarcated compact adipose tissue. Postoperative monitoring of patients with retroperitoneal liposarcoma may help in early detection of recurrence. CT is a high sensitivity and high accuracy method in diagnostic of retroperitoneal liposarcomas. Knowledge of CT patterns of recurrence may help in planning surgery. Personal information Anna A. Meldo, PhD., Head of Radiology Department of Saint-Petersburg Scientific Practical Center of Specialized Kinds of Medical Care (Oncological), St. Petersburg, Russia, [email protected] Ilya A. Burovik, MD, radiologist of Department of Radiology of N.N. Petrov Research Institute of Oncology, St. Petersburg, Russia, [email protected] References 1. Bolin TE, Bolin SG, Wetterfors J. Retroperitoneal sarcomas. An analysis of 32 cases. Acta Chir. Scard. 1988; Nov-Dec;154(11-12): Page 10 of 11

11 2. Malawer M.M, Sugarbaker P. H. Musculoskeletal cancer surgery. Treatment of sarcomas and allied diseases. Washington cancer institute; Dordrecht Kluwer Academic Publishers. 2001: 626 p. 3. Donelly, B. A. Primary retroperitoneal tumors: a report of 95 cases and a review of the literature. Surgery, gynecology and obstetrics. 1946; 83 (6): Feig, B. W. Retroperitoneal sarcomas. Surg. oncol. clinics of North America. 2003; 12 (2): Fedorov, V. D., Tsvircun V. V. Surgical treatment of patients with nonorganic retroperitoneal tumors. The Brit. j. of surgery. 1997; 84 (2): Malerba M., Doglietto G. B., Pacelli F. et al. Primary retroperitoneal soft tissue sarcomas: results of aggressive surgical treatment. World j. of surg. 1999; 23(7): Shon Ch. N., Baev S. Diagnosis and treatment of primary retroperitoneal extra-organic tumors. Khirurgiia (Sofiia). 2000; 56(3/4): Elber F. C., Rozen G., Forscher C.et al. Surgical resection and intraperitoneal chemotherapy for recurrent abdominal sarcomas. Annals of surg. oncol. 1999; 6(7): Gilbeau L., Kantor G., Stoeckle E. et al. Surgical resection and radiotherapy for primary retroperitoneal soft tissue sarcoma. Radiotherapy and oncology : j. of the Eur. society for therapeutic radiol. and oncol. 2002; 65 (3): Kim T., Murakami T., Oi H. et al. CT and MR imaging of abdominal liposarcoma. Amer. j. of roentgenol. 1996: 166 (4): Tateishi U., Hasegava T., Beppu Y. et al. Primary dedifferentiated liposarcoma of the retroperitoneum. Prognostic significance of computed tomography and magnetic resonance imaging features. J. of computer assisted tomography. 2003; 27 (5): Zanon G., Ficarra V., Beltami P. et al. Trattamento chirurgico di un voluminoso liposarcoma mixoide retroperitoneale plurirecidivo. Acta chir. Ital. 1997; 53(4): Page 11 of 11