Primary Benign Cystic Retroperitoneal Teratoma in an ...

BIOCHEMICAL AND BIOPHYSICAL JOURNAL OF NEUTRON THERAPY & CANCER TREATMENTSVOL1.NO.1 JUNE 2013 http://www.researchpub.org/journal/bbjntct/bbjntct.htmlVOL.1Primary Benign Cystic Retroperitoneal Teratomain an Asymptomatic AdultRahul Gupta, MBBS, Yella Reddy, MS, Rohit Gupta, MBBS, James S. Welsh, MD,Alice Madani, B.A., Narayan S. Hosmane, Ph.DAbstract— Primary retroperitoneal teratoma is a rare entity inadults with a distinctive imaging appearance. We describe anunusual case of a 19-year old male patient referred to our hospitaldue to a large mass in his abdomen. Radiological work-uprevealed a large retroperitoneal mass with no other masses orabnormalities. Exploratory laparotomy with tumor resection wasperformed. Histopathological diagnosis confirmed a benign cysticteratoma. The patient is doing well on follow up 5 years laterepigastric and left hypochondrium moving with respiration anddull to percussion. A clinical diagnosis of pseudopancreaticcyst was made and patient was sent for various investigations.Routine blood tests and urinalysis were all within normal limits.However, ultrasound demonstrated a large, complex, denselymixed echogenic mass, suggestive of a fatty nature to the masswith sheet like calcifications (Image 1) and no ascites.Contrast computed tomography (CT) of the abdomen revealedIndex Terms— Laparotomy, Retroperitoneum, TeratomaI. INTRODUCTIONTeratomas are uncommon neoplasms that contain derivativesof all three germ layers (ectoderm, mesoderm and endoderm).Historically, teratomas were attributed to demons, sexualmisconduct and abnormal fertilization. As with teratogenic, thename derives from the Greek word teras, meaning ‘monster’.Teratomas belong to a class of tumors known asnon-seminomatous germ cell tumor and are typically located ingonadal region. However, extragonadal sites such as thesacrococcygeal region, mediastinum, neck, diancephalon andretroperitoneum have also been reported. Retroperitonealteratomas often occur in infancy and childhood but are rare inadults. In this article, we describe an unusual case of aretroperitoneal teratoma in a 19-year old asymptomatic malepatient who subsequently, underwent successful surgicalresection.II. CASE REPORTA 19-year old male presented with upper abdominal distensionfor 3 months. He had no weight loss, bowel or urinarycomplaints. On examination, a large mass was palpable in theSubmitted on 06/05/2013. Revised on 07/24/2013.Rahul Gupta is with Northern Illinois University, DeKalb, IL 60115U.S.A. (email: grahul.md@gmail.com)Yella Reddy is with Vyedhi Institute of Medical Sciences and ResearchCentre, Bangalore, 560 066 India (email: info@vims.ac.in)Rohit Gupta is with St. Georges University, Grenada, West Indies (email:dr.guptarohit@gmail.com)James S. Welsh is with Northern Illinois University and Fermi NationalAccelerator Laboratory, Batavia, IL 60510 U.S.A. (email:shermanwelsh@gmail.com)Alice Madani is with Trinity School of Medicine, St. Vincent and theGrenadines (email: alicemadani@gmail.com)Narayan S. Hosmane is with Northern Illinois University, DeKalb, IL 60115U.S.A. (email: hosmane@niu.edu)5Image 1. Ultrasound of abdomen showing retroperitoneal space occupyinglesiona large retroperitoneal mass anterior to the head of pancreas,initially suspicious for a retroperitoneal sarcoma. However, thepresence of fat and bone inside the mass was highly indicativeof a benign cystic teratoma. CT-guided fine needle aspirationcytology (FNAC) of the mass was consistent with the diagnosisof teratoma. Chest X-ray prior to surgery, revealed no lungmetastases or lymphadenopathy.Exploratory laparotomy revealed a large cystic retroperitonealmass (Image 2) situated anterior to the pancreas and posterior tothe stomach. The tumor extended from the left hemidiaphragmdown to the umbilicus beyond the midline. Macroscopically,the encapsulated mass measured 14.86 cms x 11.03 cms (Image3). Microscopically, it appeared to be a cystic tumor withextensive necrosis and amorphous debris. There were fewmature squamous cells along with few anucleate squamouscells. Background showed an infiltrate of polymorphs,lymphocytes and plasma cells. Within the mass itself, skin

BIOCHEMICAL AND BIOPHYSICAL JOURNAL OF NEUTRON THERAPY & CANCER TREATMENTSVOL1.NO.1 JUNE 2013 http://www.researchpub.org/journal/bbjntct/bbjntct.htmlVOL.1Image 2. Exploratory laparotomy revealing the large cystic massadnexa, bone, fat and nerve were seen, consistent with atrilineage teratoma. Histopathology confirmed the diagnosis ofa primary cystic teratoma, benign in nature, with no malignantcells present. Postoperative course has been uneventful.III. DISCUSSIONImage 3. Contract CT of the abdomen shows a large retroperitoneal massanterior to the head of pancreasOverall, primary retroperitoneal teratomas constitute about1-11% [1-3] of all primary retroperitoneal tumors.Approximately half of all teratomas found in children arediscovered in first decade of life with 43-45% of retroperitonealteratomas diagnosed within the first year of life. Less than10-20% of retroperitoneal teratomas present in patients after 30years of age [4].Teratomas arise from germ cells that fail to mature normally inthe gonadal locations. These totipotent cells can differentiateinto tissue components representing derivatives of mesoderm,ectoderm and endoderm. The distribution of teratomas listed in6order of decreasing frequency is: ovaries, testes, anteriormediastinum, retroperitoneal space, pre sacral and coccygealareas, pineal and other intracranial sites, neck and abdominalviscera other than gonads. The developmental migratoryproperties of germ cells would explain teratomas in theseextragonadal sites, which generally occur along midlinestructures [1, 5].Retroperitoneal teratomas are usually asymptomatic exceptwhen compression of the surrounding structures occurs.Patients with compressive symptoms may present with backpain, genitourinary symptoms, gastrointestinal symptoms(abdominal distension, pain, nausea and vomiting), as well aslower extremity or genital edema secondary to lymphaticobstruction [1, 6].The differential diagnosis of retroperitoneal teratomas includeovarian tumors, renal cysts, adrenal tumors, retroperitonealfibromas, retroperitoneal sarcomas (usually liposarcomas),hemangiomas, xanthogranulomas, enlarged lymph nodes andperirenal abscesses [7, 8]. Testicular ultrasound is necessary torule out testicular germ cell tumor in male patients. This is anecessary step since 50% of men with retroperitoneal tumorsalso have testicular carcinoma in situ, a precursor for testiculargerm cell tumors [9].Between 1932 and 1987, 32 adult cases were reported out ofwhich 15 occurred in female patients and 17 occurred in males.Retroperitoneal teratomas in these patients were most oftenlocated near the upper pole of the kidney, mostly on the left side[5, 6]. -Malignant degeneration was higher in adults than in children,with incidences of 25.8% and 6.8%, respectively. Malignantteratomas may cause rise in serum alpha-fetoprotein (AFP) [6].Calcifications can be demonstrated in 61.5% of teratoma caseson a plain anteroposterior and lateral abdominal films and areuseful for the pre-operative diagnosis [1]. Such calcificationsmay be within the tumor or on the rim of the cyst wall. Eventhough 74% of benign teratomas contain calcification, they alsooccur in 12.5% of malignant teratomas [10].Several imaging modalities elucidate different characteristicsof a teratoma. For example, ultrasound can identify the cystic,solid or complex components of the tumor [11]. The cysticportion may be further differentiated into sebum, non-fat fluidand structures resembling fetal parts. However, ultrasound hasits limitations as Davidson et al found that ultrasound poorlyidentified fat and calcifications, which are suggestive ofteratoma.CT has several advantages over ultrasound. First, it gives morespecific information on the fat, proteinaceous fluid andcalcification components of the teratoma through Hounsfieldunits, which allows quantitative comparison of substances ofdifferent radiodensities. The presence of fatty portions of thetumor in the horizontal interface with dependent fluid, whichprobably represents sebum, is virtually pathognomonic of ateratoma [11, 12]. However, a fat fluid level has also beendescribed in case of a well differentiated liposarcoma of theretroperitoneum [13]. Second, CT appears superior to

BIOCHEMICAL AND BIOPHYSICAL JOURNAL OF NEUTRON THERAPY & CANCER TREATMENTSVOL1.NO.1 JUNE 2013 http://www.researchpub.org/journal/bbjntct/bbjntct.htmlVOL.1ultrasound at defining extent in to surrounding organs and forevaluating the cyst wall [11].Magnetic resonance imaging (MRI) and angiography offerother benefits. MRI is superior to both ultrasound and CT indefining the anatomical relationship of the teratoma withadjacent organs and local tumor spread [14, 15]. MRI can alsodistinguish fluid, fat, calcium and soft tissue elements, as wellas predict resectability and evaluate recurrence [16].Angiography is beneficial for detecting the presence ofhypervascularity, arterial encasement and organ invasion,features often suggesting malignancy [17].In our case, the initial differential diagnosis includedretroperitoneal sarcoma. Even with modern preoperativeimaging studies, retroperitoneal sarcomas can be confused withretroperitoneal teratomas [18]. Pre- or post-operative radiationtherapy can be challenging in retroperitoneal sarcomas becauseof radiosensitive adjacent normal structures and the need forrelatively high doses, especially in unresectable cases or whenpositive margins are left behind. In such situations, fast neutrontherapy [19] or more recently, intensity-modulatedradiotherapy, intraoperative electron beam radiotherapy orproton therapy has been considered [20]. While retroperitonealsarcomas are often treated with a combination of preoperativeradiation therapy and surgery [21, 22], retroperitonealteratomas, if benign, usually do not warrant radiotherapy.IV. CONCLUSIONIn summary, teratomas can macroscopically be divided into 2categories: cystic or solid. Cystic teratomas are mostly benign,containing sebaceous materials and mature tissue types. On theother hand, solid teratomas are often malignant and composedof immature embryonic tissues in addition to adipose,cartilaginous, fibrous and bony components. The prognosis isexcellent for benign retroperitoneal teratoma if completeresection can be accomplished.ACKNOWLEDGMENTDr. Rahul Gupta would like to thank Rikin Shah, MD student,for giving his valuable time in helping proofread and evaluatethis article. We gratefully acknowledge KishwaukeeCommunity Hospital Foundation for the support of this work.[5] Engel RM, Elkins RC, Fletcher BD. Retroperitoneal teratoma. Review ofthe literature and presentation of an unusual case. Cancer 1968; 22:1068-1073.[6] Lambrianides AL, Walker MM, Rosin RD. Primary retroperitonealteratoma in adults. Urology 1987; 29: 310-312.[7] Pantoja E, Llobet R, Gonzalez-Flores B. Retroperitoneal teratoma: ahistorical review. J Urol 1976; 115: 520-523.[8] Pandya JS, Pai MV, Munchhala S. Retroperitoneal teratoma presenting asacute abdomen in an elderly person. Ind Jou Gastroentero 2000; 19;89-90.[9] T. Gilligan, P.Kantoff. Extragonadal germ cell tumors involving themediastinum and retroperitoneum. UpToDate Patient Preview, W.K. Oh,Ed., UpToDate, Waltham, Mass, USA, 2009.[10] Bruneton JN, Diard F, Drouillard JP, et al. Primary retroperitonealteratoma in adults: Presentation of two cases and review of the literature.Radiology 1980; 134; 613-616.[11] Davidson AJ, Hartman DS, Goldman SM, Mature teratoma of theretroperitoneum: radiologic, pathologic, and clinical correlation.Radiology 1989; 172: 421-425.[12] Billmire DF, Grosfeld JL. Teratomas in childhood: analysis of 142 cases.J Pediatric Surg 1986; 21: 548-551.[13] Smirniotopoulos JG, Chiechi MV. Teratomas, dermoids, and epidermoidsof the head and neck. Radiographics 1995; 15: 1437-1455.[14] Bellin MF, Duron JJ, Curet PH, Dion-Voirin E, Grellet J. Primaryretroperitoneal teratoma in the adult: correlation of the MRI features withCT and pathology. Magn Reson Imaging 1991; 9: 263-266.[15] Choi BI, Chi JG, kim SH, Chang KH, Han MC. MR imaging ofretroperitoneal teratoma: correlation with CT and pathology. 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