Retroperitoneal Area Research Articles

A young patient with heart failure was diagnosed with extra-adrenal paraganglioma: a case report

BackgroundWe present a case of pelvic paraganglioma that presented with heart failure as the primary symptom.Case presentationA 35-year-old man was admitted to hospital due to heart failure. Contrast-enhanced pelvic CT showed mass shadows in the posterior wall of the bladder and multiple enlarged lymph nodes in the retroperitoneal area. Ultrasound-guided puncture was performed, and the pathologic diagnosis was extra-adrenal paraganglioma. The patient refused any chemotherapy and died within six months of diagnosis.ConclusionThe possibility of neuroendocrine-related tumors, for example paragangliomas, should be considered in young patients with heart failure, especially those with concomitant hypertension and diabetes.

Follicular lymphoma manifests as multiple erosive and proliferative lesions of the oral mucosa: case report and brief literature review

BackgroundErosion is one of the most common and basic lesions of oral mucosal diseases. Long-term refractory oral erosions, induced by autoimmune blistering diseases, infectious diseases, malignant diseases, and some rare conditions, may substantially reduce the quality of life of patients or even constitute a life-threatening condition, resulting in a clinical dilemma regarding the accurate diagnosis and precise management of these diseases. As a special type of malignant lymphoma, most lesions of follicular lymphoma (FL) in the oral mucosa present as masses or swelling of the oral mucosa, while emerging novel presentations lead to intractable diagnoses. Hence, diagnostic algorithms for such diseases are clinically required. Case presentationA 55-year-old female patient presented to the clinic with long-lasting oral mucosal erosions and proliferative lesions. Blood tests, pathological examinations of oral lesions including haematoxylin–eosin (HE) staining, and direct immunofluorescence precluded all of the potential diagnoses described previously. Unexpectedly, positron emission tomography/computed tomography (PET/CT) and abdominal CT of the patient revealed a dense mass in the retroperitoneal area, and the final diagnosis of the retroperitoneal mass was FL. After three courses of chemotherapy conducted by the haematologist, the erosion and proliferative lesions in the patient's oral mucosa had significantly improved. HE and immunohistochemical staining results of intraoral lesions also confirmed it as oral FL. The successful diagnosis of FL in this case is of great clinical significance, as the oral and abdominal FL were treated in a timely manner to avoid unfavourable outcomes.ConclusionsTo the best of our knowledge, this is the first case of FL that exhibited widespread erosions interspersed with proliferative lesions. Clinicians should be aware of oral FL or seek systemic factors in the presence of similar refractory oral erosions when treatment is non-responsive and the diagnosis is intractable.

Association of preoperative Enzian score with postoperative fertility in patients with deep pelvic endometriosis

IntroductionEndometriosis is a chronic inflammatory disease with a negative impact on fertility. The Enzian classification provides a precise description of deep pelvic endometriotic lesions, especially in the retroperitoneal area, from preoperative pelvic MRI scans. However, it is not known if it is correlated with postoperative fertility. Study objectiveTo determine if there is an association between the preoperative Enzian score and postoperative fertility after deep pelvic endometriosis surgery. DesignWe conducted a descriptive, retrospective study using information from the ENDOREN database. SettingThis was a retrospective study at the Department of Obstetrics and Gynecology at Rennes University Hospital (France) from January 2013 to May 2019 Patients and interventionsWe used information from the ENDOREN database that included all women who underwent surgery for deep endometriosis and wish to conceive. This surgery was intended in a view to achieve a complete removal of endometriosis. MeasurementsThe Enzian score was calculated from preoperative MRI scans, and total, spontaneous, and after In Vitro fertilization (IVF) live births and pregnancies outcomes were collected from the patients'computerized medical records. Univariate and multivariate analysis was performed. ResultsSixty-eight patients were included. The live-birth rate was 35% (24/68). According to the Enzian classification, 25 patients (35%) were classified in compartment A, 64 patients (94%) in compartment B, and 27 (40%) in compartment C. In multivariate analysis, positive predictor of live birth was single Enzian B score (OR=4.7[1.21; 18.81], p = 0.03), negative predictors were uterine adenomyosis and a history of endometriosis surgery. In multivariate analysis, positive predictor of spontaneous live birth was EFI score ≥7 (OR =22.434; CI [1.138; 442.190]). In multivariate analysis, positive predictor was Enzian A score (OR=15.9[2.2; 114.7], p = 0.006), and negative predictors was uterine adenomyosis and Enzian B score (OR=0.01[0; 0.495], p = 0.02) for live birth after IVF. ConclusionThe present retrospective study cannot strongly conclude about fertility and correlation with Enzian score because the groups are too small. However, it seems that when solely the compartment B is involved by endometriosis, complete full removal of endometriosis leads to better post-operative live births results. Other studies must be done to determine if Enzian classification based on preoperative pelvic MRI could be clinical value in the decision-making strategy for managing infertile patients with deep pelvic endometriosis.

Polypoid Cystitis in a dog. A case report.

ABSTRACT. Polypoid cystitis is a rare disease of younger male dogs. The aim of this article is to report an incidence of polypoid cystitis, which was observed in a dog. The 11-year-old dog had a 3-month history of hematuria. Upon surgical approach to the retroperitoneal area an irregularly thickened wall was revealed, and additionally six (6) cysts 1-6 mm in diameter protruded from the mucosal surface. Histological examination confirmed transitional cell hyperplasia covering a core of proliferating connective tissue, edema and a neutrophilic inflammatory cell infiltrate with areas of ulceration and hemorrhage. These lesions are consisted with polypoid cystitis which is is a rare-benign disease, histopathology is the means of definitive diagnosis and it is best treated with surgical cystotomy.

First observation of intraocular extranodal natural killer/T-cell lymphoma secondary to a retroperitoneal tumour: a case report and comparative review

BackgroundVitreoretinal lymphomas are difficult to diagnose due to their insidious onset and inaccessible focal points. Natural killer/T-cell derived malignancies are rare as intraocular lymphomas and usually have a rapid progression and a poor prognosis. Therefore, it is essential to make a definite diagnosis, especially differentially with B-cell-derived lymphomas, which account for most cases of vitreoretinal lymphomas.Case presentationThis case report describes a 55-year-old female reporting a 10-month history of painless decline in her vision of the right eye. Optical coherence tomography of the patient revealed hyperreflective nodules and irregular humps in the retinal pigment epithelium layer. The right vitreous was aspirated for diagnostic assessment, revealing an interleukin-10 level of 39.4 pg/mL and an interleukin-10/interleukin-6 ratio of 1.05. The right vitreous humor was positive for Epstein–Barr virus DNA. Upon a systemic examination, a high metabolic nodule was found in the retroperitoneal area and proven to be positive for Epstein–Barr virus-encoded mRNA, CD2, CD3ε, TIA-1, and Ki-67. Considering the homology of the two lesions, the patient was diagnosed with metastatic vitreoretinal lymphoma secondary to retroperitoneal extranodal natural killer/T-cell derived lymphoma. The patient received systemic chemotherapy and regular intravitreal injections of methotrexate. Her visual acuity of the right eye had improved from 20/125 to 20/32 at the latest follow-up. No new lesions were found.ConclusionsA definitive diagnosis of vitreoretinal lymphoma is challenging. On some occasions in which pathological evidence is missing, the available examination results and clinical observations must be comprehensively considered. This study herein summarized pertinent pieces of literature and reports and reviewed available practicable methods to make a definitive diagnosis of intraocular extranodal natural killer/T-cell lymphoma, which was particularly distinct from the common diffuse large B-cell lymphomas.

The epidemiology of desmoid tumors in Denmark

Introduction/aimThe epidemiology, demographic, clinical, treatment, and healthcare resource utilization (HRU) characteristics of desmoid tumor (DT) patients treated at two sarcoma centers in Denmark is described. MethodsUsing Danish health registers, we studied DT patients treated at two sarcoma centers between 2009 and 2018. For each patient, ten persons from the general population were randomly matched on birth year, sex, and region of residence. ResultsOf the 179 DT patients identified, 76% were female and the median patient age was 38 years at diagnosis (interquartile range: 31–50). An average annual incidence of DTs over the study period was 3.2 per 1000,000 individuals with the observed annual incidence of DTs ranging from 2.2 (2011) to 4.3 (2017) per 1000,000 individuals. No notable linear time trend in incidence was observed. Anatomical DT sites included extra-abdominal (49%), abdominal wall (40%), and intra-abdominal or retroperitoneal areas (8%). In total, 56% of patients were initially treated surgically. However, while 75% of patients diagnosed with DT between 2009 and 2014 were initially treated surgically, this was true for only 32% of patients diagnosed with DT between 2015 and 2018. A total of 56% of DT patients used chemotherapeutic agents, tyrosine kinase inhibitors, NSAIDs, opioids, antidepressants, or steroids at some point during the three years before their DT diagnoses. In contrast, 70% of surgically treated and 63% of non-surgically treated patients used one of these drugs in the subsequent three years, including NSAIDs (45% surgical vs. 33% non-surgical), opioids (39% surgical vs. 27% non-surgical), and steroids (22% surgical vs. 18% non-surgical). The average number of inpatient and outpatient visits, days of hospitalization, and additional surgical procedures were higher among DT patients than the comparison cohort. ConclusionDTs are rare but have a large impact on patients’ health, HRU, and medication utilization.

A Huge Liposarcoma: Case Study

A 53-year-old had complaints of vague abdominal pain for the past few months. The patient had a history of diabetes mellitus, hypertension, and iron deficiency. The pain was aching, mild, intermittent, non-radiating, and generalized. An ultrasound of the abdomen, CT scan and MRI were recommended. After initial examination and reports, the patient was diagnosed with a retroperitoneal tumor. The liposarcoma found was dedifferentiated, high grade, and retroperitoneal. The tumor extended to the inked resection margin, and was large, with 24 cm and 14 cm in greatest dimension measurements. The liposarcoma was lipomatous and solid, with hot spots of mitosis. In terms of treatment, surgery was recommended to remove the enlarged mass. Two heterologous fragments, which were different in morphology, size, and color, were obtained from the retroperitoneal area during surgery. The mass was a huge grade 3 liposarcoma with a mitotic rate of > 20 mitoses per 10 high-power fields (HPF). The examination and diagnosis included some special studies such as immunohistochemistry assay, which was positive for p16, vimentin, and MDM2. A post-operative scan showed that there was no evidence of recurrence or residual retroperitoneal tumour. Chemotherapy was initiated by the Oncology Department.

Major Surgical Resections in Abdominopelvic Sarcomas: Clinical Features and Results of 38 patients: A Tertiary-Center Experience.

Introduction: Sarcomas with mesenchymal origin located in the abdominal cavity or retroperitoneal space are rare. They might reach large dimensions due to the non-specific and late onset of clinical symptoms. In this study we aim to provide the outcomes of 38 cases. Methods: Thirty-eight patients, whose data had been registered and analyzed completely in a prospective manner, were enrolled in the study. Demographic Findings, Primary-Recurrent Status of the disease, surgical method applied (R0-1-2), additional organ resections, Morbidity and Mortality rates, HIPEC application, Histopathological results and overall survival outcomes during follow-up were evaluated in the enrolled cases. Results: Thirty-eight (38) patients were operated on due to soft tissue sarcomas located in the abdominal and retroperitoneal area. The mean age of patients was 57.63 +- 15.38. The localization rates of retroperitoneal, abdominal and visceral tumors were 28%, 58%, and 12%, respectively. The mean tumor size was 12.96 cm +- 9.62. Twenty-seven patients (71%) underwent R0 resection, 7 patients (18%) underwent R1 resection, 4 patients (10%) underwent R2 resection. Additionally, sarcomatosis was detected in 6 patients and these patients underwent Cytoreductive Surgery+HIPEC. The first 30-day mortality and morbidity rates were 10.5% (4 patients) and 44% (17 patients), respectively. Conclusion: Surgery is the gold standard treatment of this condition. The most important stage in the management of the condition is the discussion of these cases in multidisciplinary teams in centers experienced in this disease in terms of prognosis and local recurrence and deciding on the treatment strategy based on these discussions.

Pedunculated Intraperitoneal Lipoma Presenting as Ovarian Torsion: A Case Report

A lipoma is a very common (prevalence 39%) benign soft tissue tumour that is composed of mature fat. Lipomas, though common on external surface of body, also have been reported in mediastinum, chest wall, thorax, retroperitoneal areas and pelvis. In Gastrointestinal Tract (GIT), lipomas are mainly found in the submucosa and subserosa of the small and large intestine. An eightyear-old female child presented with a feature suggesting torsion of the dermoid ovarian cyst. The clinical features included sudden abdominal pain, vomiting and other symptoms suggesting a differential diagnosis of appendicitis or an ovarian cause. Serum markers for carcinoma were normal. The Contrast Enhanced Computed Tomography (CECT) showed a right iliac fossa fat density with few internal septations and Magnetic Resonance Imaging (MRI) confirmed the torsion of the pedunculated mass and histopathological examination showed the mass as lipoma. The site of the lipoma, presented in this case, is rare. Though the presentation of intraperitoneal lipoma is rare, this should be considered as differentials in young patients presenting with features of ovarian torsion. The presentation of intraperitoneal lipoma especially in young patient is rare which is mostly an incidental finding in a laparotomy and mostly present as a case of obstruction or abdominal pain.

İntranodal Palisad Myofibroblastoma: Klinisyenler ve Patologlar için Histopatolojik ve Klinik İnceleme

Intranodal palisaded myofibroblastoma (IPM) is a kind of mesenchymal tumor with benign behaviour. The origin of this tumor is differentiated smooth muscle cells and myofibroblasts. This is a rare entity and differential diagnosis from malignant tumors is important for clinicians and pathologists. The etiology has not been explained adequately. Age range is between 2nd and 8th decades of the life and it is seen more frequently in males. Inguinal region is the most common localization but has been reported in other localizations including submandibular and retroperitoneal areas. Total excision of the tumor is the treatment in these cases. Recurrence is very rare and there is no report about metastasis. In conclusion IPM is a rare entity and it is commonly misdiagnosed as metastasis. Kaposi Sarcoma and schwannoma are the most common two spindle cell neoplasias. Be aware of this unique entity is important because wrong diagnosis causes dangerous management strategies.

Definition of pelvic venous disease and the new SVP classification

Chronic pelvic pain (CPP) is often diagnosed by gynecologists. In recent years, the realization that venous insufficiency in the pelvic or retroperitoneal area can also cause CPP has led to the involvement of vascular physicians in the diagnosis and treatment. Differentiating pelvic venous disease (PeVD) from gynecological, internal or even orthopedic complaints poses a challenge. A comprehensive study of the patient"s medical history and a detailed description of symptoms are of paramount importance. The symptoms of PeVD depend on the veins involved. Whereas pelvic pain is mainly an expression of an insufficiency of the ovarian vein and/or the internal iliac vein, left flank pain and hematuria are caused by an obstruction of the renal vein. Symptoms may also be associated with atypical varicose veins in the vulva, perineum, or legs. Anatomical gaps, pelvic escape points, allow them to communicate with the branches of the insufficient internal iliac veins and with the ovarian. As an effective tool for reporting PeVD patient populations the symptoms-varicespathophysiology (SVP) classification was published in 2021. It is thought to be the initial point of both the treatment standard and identifying homogenous patient populations for clinical trials.

Cecal epidermoid cyst: a neonatal case with clinicopathological consideration

BackgroundOnly 10 cases of cecal epidermoid cyst (CEC) have been reported in the literature. Furthermore, its pathogenesis remains unclear. We report a rare case of congenital CEC in neonate, and discuss its clinicopathological findings.Case presentationA cystic lesion was incidentally identified in the retroperitoneal area of the abdominal right lower quadrant during a routine prenatal ultrasonography (US), prompting an ileocolectomy 3 days after birth. This congenital cyst was composed of mucosal lining cells and submucosal connective tissues, and the inner lining mucosa was composed of stratified squamous epithelium and focally mucin-producing ciliated epithelium. Based on the macroscopic and microscopic findings, the cystic lesion was diagnosed as a congenital cecal epidermoid cyst.ConclusionsThe management of a fetal abdominal mass should be tailored individually, considering that epidermoid cysts can occur in the cecum during the perinatal period. We report the clinicopathological findings in this case, including its possible pathogenesis.

Utero-placental apoplexy during induction of therapeutic abortion in a 18-week pregnancy.

Utero-Placental Apoplexy, or Couvelaire Uterus, is a third-trimester major obstetrical complication, occurring especially during labor. It consists of placental abruption followed by an acute intradecidual hemorrhage produced by the rupture of the uterus-placental spiral arterioles leading to a retroplacental hematoma. This hemorrhage infiltrates the uterine wall up to intra- and retro-peritoneal areas. We provide a case report, on which no previous literature is available, of a utero-placental apoplexy during induction of therapeutic abortion.

Giant lymph node hyperplasia (Castleman's disease) in the retroperitoneal area

Giant lymph node hyperplasia (Castleman's disease) in the retroperitoneal area

Clinical Characteristics and Treatment Outcome of Paediatric Rhabdomyosarcoma; A Retrospective Review.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. This paper aimed to assess the stage, site and treatment outcome among RMS patients. A retrospective chart review was completed from January 2011 to December 2017 of patients that presented to the Department of Paediatric Oncology, Shaukat Khanum Memorial Cancer Hospital, Lahore, Pakistan, for the management of RMS. Data collection included clinical characteristics, staging, grouping, risk stratification, treatment plan, radiotherapy doses and treatment outcome. Among 24 subjects, there were a total of 13 (54.2%) males and 11 (45.8%) females. The median age at the time of diagnosis was 2.5 years (range: 0.75-17 years). The majority of the subjects (91.7%) were <10 years of age. The median follow-up time was 0.6 years. According to the Children's Oncology Group Classification, 4 (16.7%) subjects were classified as low risk, 14 (58.3%) subjects were rated as intermediate risk and 6 (0.25%) subjects were stratified as high risk. The most common primary tumour site was genitourinary (62.5%) and abdomen/retroperitoneal (20.8%) regions. At the time of analysis, nine (37.5%) subjects had died because of the disease, 12 (50%) were alive with no evidence of disease and one subject had a recurrence of disease and was alive. One subject had abandoned the therapy and another was lost to follow-up. Patients with RMS presented at the late stages of the disease and it most frequently affected genitourinary and abdomen or retroperitoneal areas. Overall, RMS was found to have a poor outcome to therapy.

Enfermedad relacionada con IgG4

Immunoglobulin G4-related disease (IgG4-RD) is a fibro-inflammatory condition that can involve all the systems of the organism. This disease has been described relatively recently, in the early decades of the 21st century. Due to this, its aetiology and pathophysiology are not currently sufficiently established. Proof has been growing that the pathogenesis of the disease has an autoimmune foundation, with participation of the memory B cells, T follicular helper (Tfh) cells, T CD4 lymphocytes and macrophages. Initially, the elevation of the IgG fraction 4 (IgG4) serum levels of these patients made it seem that they might be of value in aetiopatogenesis and diagnosis. However, it has later been seen that only about 60% of the patients present elevated serum IgG4 levels. Although almost any organ can be affected, predilections have been defined, principally the salivary glands, orbits and lacrimal glands, pancreas and biliary tree, lungs, kidneys, aorta and retroperitoneal area, meninges and thyroid gland. All the organs affected by IgG4-RD share several histopathological features: lymphoplasmocytic infiltrate with abundant positive IgG4 plasma cells, storiform fibrosis, obliterative phlebitis and eosinophil presence. Diagnosing is complex, given that it requires a combination of clinical, analytical, radiological and histopathological examination. Numerous differential diagnoses also have to be excluded.

Hydatid Cyst Treatment and Management in Retroperitoneal Organs; Is Percutaneous Drainage an Option?

To evaluate patients who cyst hydatid (CH) in their retroperitoneal space and organs in order to determine a standard treatment option for CH. The files of 56 patients who were treated for CH in our clinic were evaluated retrospectively. All patients underwent either percutaneous drainage (PD) or surgery. Patients were divided into two groups as PD (Group one) and surgery groups (Group two). Preoperative and postoperative results were compared statistically. 31 of 56 patients were male. Mean age of the patient was 39.7 (10-85). 16 patients had been treated with PD and 40 with different surgical interventions such as total cystectomy, partial cystectomy, partial nephrectomy, total nephrectomy, surrenalectomy, and laparoscopic partial surrenalectomy. Patients' followed up was 18 months (6-38m). Relapse was seen in 1 patient who underwent PD. On comparing the results, hospitalization period was prolonged in the surgical group with enlarged cyst presence. CH presence in the retroperitoneal area is rare. PD, a minimally invasive method, has the potential to be the standard treatment option as it can be performed safely in selected patients. However, currently surgical treatment is considered as the first treatment option after CH diagnosis.

Usefulness of 99mTc-ASC lymphoscintigraphy and SPECT/CT in the evaluation of rare lymphatic disorders: Gorham-Stout disease, lymphangioma, and lymphangioleiomyomatosis.

The purpose of this study was to investigate the role of 99mTc-antimony sulfide colloid (ASC) lymphoscintigraphy and single photon emission computed tomography/computed tomography (SPECT/CT) in the evaluation of rare lymphatic disorders, including Gorham--Stout disease (GSD), lymphangioma, and lymphangioleiomyomatosis (LAM).Nine patients suspected to have rare lymphatic disorders were included in this retrospective study. All patients underwent 99mTc-ASC lymphoscintigraphy and SPECT/CT to evaluate the lesions. The lymphoscintigraphy results were compared with the clinical and immunopathological findings.99mTc-ASC lymphoscintigraphy and SPECT/CT could provide lymphatic draining and anatomical information for rare lymphatic disorders. Among the 9 patients, 3 were diagnosed with GSD (1 female, 2 males; aged 15–34 years, range 27.0 ± 10.4 years), 3 with lymphangioma (1 female, 2 males; aged 17–42 years, range 32.0 ± 13.2 years), and 3 patients were diagnosed with LAM (3 females; aged 33–50 years, range 43.7 ± 9.3 years]. GSD is characterized by multiple bone destruction, including spine, ribs, ilium, pubis, ischium, and femur. The tracer uptake of involved bones and soft tissue around bone is increased, accompanied by chylothorax, chylopericardium, and chylous leakage in abdominal and pelvic cavity. Lymphangiomas present as multiple cystic lesions with increased tracer uptake in the peripancreatic, retroperitoneal, and iliac areas, and in the abdominopelvic cavity. LAM presents as multiple thin-walled cysts in the bilateral lungs and multiple retroperitoneal enlarged lymph nodes with increased tracer uptake.99mTc-ASC lymphoscintigraphy and SPECT/CT could comprehensively and specifically detect some rare lymphatic disorders, namely, GSD, lymphangioma, and LAM. This technique is useful for the evaluation of GSD, lymphangioma, and LAM.

Abstract 6213: Extracellular vesicles MDM2-DNA derived from dedifferentiated liposarcoma induces MMP2 production from preadipocytes

Abstract Dedifferentiated liposarcoma (DDLPS) is molecularly characterized by wt p53 and MDM2 gene amplification causing MDM2 protein over-production, the key oncogenic process in DDLPS. Commonly located in fat-bearing retroperitoneal areas, almost 60% of DDLPS patients undergo multifocal recurrence, typically amenable to palliative treatment only, and occasionally develop distant metastasis. These factors lead to an abysmal 10% 10 year overall survival rate. Tumor cell-derived extracellular vesicles (EVs) can facilitate loco-regional malignancy dissemination by depositing molecular factors that participate in the development of pre-metastatic niches for tumor cell implantation and growth. High number of MDM2 DNA molecules was identified within EVs from DDLPS patient serum (ROC vs normal; 0.95) as well as from DDLPS cell lines. This MDM2 DNA could be transferred to preadipocytes (P-a), a major and ubiquitous cellular component of the DDLPS tumor microenvironment (TME), with subsequent P-a production of matrix metalloproteinase 2 (MMP2), a critical component in the metastatic cascade. Since multifocal loco-regional DDLPS spreading is the main cause of the remarkably high lethality of this disease, a better understanding of the underlying oncogenic processes and their regulatory mechanisms is essential to improve the outcome of this devastating disease. Citation Format: Lucia Casadei, Federica Calore, Ameya Deshmukh, Abeba Zewdu, Paolo Fadda, Danielle Braggio, Martin Wabitsch, Carlo M. Croce, Dina Lev, Raphael Pollock. Extracellular vesicles MDM2-DNA derived from dedifferentiated liposarcoma induces MMP2 production from preadipocytes [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6213.

Primary retroperitoneal hydatid cyst in pancreatic head region

A hydatid cyst in retroperitoneal space is uncommon and one in the pancreatic head region is rare. We hereby report a case of a 20-year-old male presenting with a retroperitoneal hydatid cyst of the pancreatic head region. Investigations revealed no hydatid cysts in other organs of the body. The diagnosis was confirmed at laparotomy and partial pericystectomy was performed. Hydatid cyst should be considered in the differential diagnosis of cystic lesions of retroperitoneal area.------------------