Vol 13, Issue 12, 2020 Online - 2455-3891 Print - 0974-2441 RETROPERITONEAL LIPOSARCOMA-EXCISION OF RETROPERITONEAL TUMOR AND RIGHT NEPHRECTOMY: A CASE STUDY NAMALA VENKATA YASESWI, VINAY KUMAR T*, KOMMURI VYDURYAM, ZAKIRA BEGUM KOMMURI JOY SHALEM Department of Pharmacy Practice, Nirmala College of Pharmacy, Atmakur, Mangalagiri, Andhra Pradesh. Email: vinaykumartheendra@gmail.com Received: 18 February 2020, Revised and Accepted: 02 October 2020 ABSTRACT A 64-year-old woman was referred to the hospital with complaints of abdomen right side tightness with discomfort for 1 month. Computed tomography scan of abdomen investigation revealed large retroperitoneal mass measuring 18.9 cm × 12.1 cm displacing the inferior vena cava right kidney and renal vessels in right hypochondriac and lumbar regions of the abdomen with large fat components. She underwent surgery, which involves the resection of tumor mass with non-affected surgical margins. These tumors tend to be resistant to radiotherapy or chemotherapy. Among the most important prognostic factor related to survival is surgery with non-affected margins. A review on etiology, pathophysiology, pathological classification, and grading is explained in literature review. Keywords: Liposarcoma, Retroperitoneal, Sarcoma, Well-differentiated, Radiotherapy, Chemotherapy. INTRODUCTION Retroperitoneal liposarcoma refers to liposarcoma arising from abdomen and pelvic retroperitoneal adipose tissue [1]. According to Windham and Pisters (2005), liposarcoma accounts for <1% of systemic malignant tumors; retroperitoneal liposarcoma is the most common type (41%) of retroperitoneal soft tissue sarcoma followed by leiomyosarcoma and malignant fibrous histiocytoma. Onset of age is 55–75 years, slightly more common in men than in women with a ratio of 1.3:1 for men to women consisting of 68.3% retroperitoneal tumor and 11.6% liposarcoma [2]. Among 119 cases of retroperitoneal liposarcoma, the ratio of male to female incidence was 1.9:1 and the median age at onset was 58 years old [3]. Immune deficiency and immunosuppressive drugs are associated with the pathogenesis of retroperitoneal soft tissue sarcoma [4]. It is reported that patients with systemic lupus erythematosus developed diffuse infiltrative retroperitoneal mucinous liposarcoma [5] after treated with steroid hormone for 13 years. Individuals with a family history of lipoma or liposarcoma are more susceptible to developing retroperitoneal liposarcoma [6]. Retroperitoneal liposarcoma has been reported to occur successively in two compatriots with a family history of malignant fibrous histiocytoma. The pathogenesis of retroperitoneal liposarcoma remains unclear [9] and may be related to molecular mechanism [10]. Mechanism of MDM2-p53 MDM2 gene (human homolog of the murine double minute type 2) located at 12q13-15 region shows constant amplification in well- differentiated liposarcoma [11]. MDM2 is a p53-specific E3 ubiquitin ligase and principle cellular antagonist of P53, acting to limit the p53 growth-suppressive function in unstressed cells [12]. In healthy body, the precise balance between p53 and MDM2 guarantees the normal proliferation and differentiation of tissue cells. If MDM2 is overamplified, p53 activity is inhibited, resulting in uncontrollable cell proliferation. This may be related to the pathogenesis of retroperitoneal liposarcoma [13]. Mechanism for prune-nm23-H1 Prune the human homolog of Drosophila prune gene, located in 1q21-23, encodes a protein that can bind to nm23-H1 [14] (nucleoside-diphosphate kinase) to downregulate its activity. The nm23-H1 may inhibit cell proliferation and tumor metastasis. The balance and precise coordination between prune and nm23-H1 expression present in healthy human bodies, in contrast, overexpression of prune gene is found in liposarcoma, with downregulation of nm23-H1 activity [15]. This may be one of the molecular mechanisms responsible for the pathogenesis of liposarcoma [16]. CASE REPORT The study was conducted as per approval given by IRB with reference no. IRB/NCPA/12/2019. A 64 years female patient admitted in hospital with chief complaints of abdomen right side tightness with discomfort for 1 month and decreased appetite and weight loss. She had a history of diabetes mellitus and hypertension on regular medication. Computed tomography (CT) scan of chest Impression • Known case of retroperitoneal tumor • Small patchy fibrotic lesions are seen in the right lower lobe • No soft tissue density nodules seen in both lungs. CT coronary angiogram Impression Total calcium score of 294 multiple calcified and mixed plaques in proximal mild left anterior descending. Moderate stenosis is seen in proximal left anterior descending (52% diameter stenosis) calcified plaques in proximal left circumflex artery and in obtuse marginal causing mild stenosis (29% diameter stenosis) discrete calcified plaques in proximal and mild right coronary artery no significant stenosis. CT scan of abdomen (plain and contrast) Impression Large retroperitoneal mass measuring 18.9 cm × 12.1 cm right kidney and right vessels in right hypochondria and lumbar regions of the abdomen with large fat components multiple small calcified fibroids in the uterus. DISCUSSION The first description of a retroperitoneal lipomatous tumor excision was made in 1761 by Giovanni Battista Morgagni during the autopsy of a 60-year-old woman. These tumors are uncommon malignant © 2020 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4. 0/) DOI: http://dx.doi.org/10.22159/ajpcr.2020.v13i12.37183 Case Report