Neurenteric Diagnosed by Technetium 99m Pertechnetate Sequential

Joachim Kropp, Dieter Emons, and Cuno Winkler Institutfur Klinische und Experimentelle Nuk/earmedizin; und Kinderk/inik der Universitaisk/iniken, Bonn, FRG

Neurentenccystsare rare congenitalanomalieswhichpresentas mediastinaltumors associatedwith vertebraanomalies.Two-thirdsof themarelinedwith gastiic mucosaandare potentiallylifethreatening.An exact differentialdiagnosisis difficultpreoperativelybut is absolutelynecessarybecauseof the graveprognosisif left untreated.We presenta casein which[@‘Tc@pertechnetatesequentialscintigraphydemonstratedgastricmucosain the cyst andhelpedto confirmthe diagnosis.Thescintigraphicfindingsarecorrelatedwith radiologic, sonographic,andpathologicfeatures.

J NucI Med 28:1218—1220,1987

eurenteric are rare tumors of the posterior roentgenographshowed in addition to the known vertebra mediastinum. They are partially or completely lined by anomalies a right-sided mediastinal mass from T2 to T8 (Fig. gastric mucosa and are associated with congenital 1). Because of normal urine catecholamines the differential anomalies ofthe vertebrae. Fistulae or solid connections diagnosis of a neuroblastoma was ruled out. to the (CNS) are possible, and The patient often passed black, tarry stools. Because of the combination of abnormalities of the vertebrae, mediastinal therefore they are ascribedto the split notochord syn tumor, and passage of black tarry stools a neurenteric cyst drome. An early preoperative diagnosis is absolutely with intermittent gastric mucosa bleeding was suspected. necessary because of the complications of such cysts Because ofthe a fistula between the cyst and the which lead to a grave prognosis. Such complications was suspected, but it was not confirmed by are first due to acid and pepsin-containingsecretionsof myelography. The upper gastrointestinal series showed ab the gastric mucosa in the cyst which lead to ulceration sence ofrotation ofthe colon and a small tumor with a central and perforation, second, to CNS infections if there is a recessionon the back wall of the duodenal bulb which im fistula between the cyst and the spinal canal. For the pressed gastroscopically as a papillary bulging of the mucosa. purpose of an early diagnosis, technetium-99m This finding suggested, that this was the point of connection (99mTc)pertechnetatescintigraphy can be used. This is a of a second fistula to the 0! tract. The computer tomogram simple, noninvasive technique and can be applied with showed the known myelodysplasia and the tumor of the out hazard to the patient. It demonstrates the ectopic posterior mediastinum with soft-tissue density (Fig. 2). A cyst could not be diagnosed with certainty. The cyst was not gastric mucosa of the cyst and is therefore helpful in visualized by sonography. differential diagnosis. To confirm the diagnosis of an neurenteric cyst sequential @TcO4scintigraphy was performed. Imaging was done with CASE REPORT a large field-of-view (LFOV) gamma camera°using a sequen tial technique. Immediately after i.v. injection of 2 mCi (74 A 6-wk-old female infant developed meningitis and was MBq) [99mTcJpe@echnetate the first picture was obtained, admitted to our institution. A and spot films followed by images every 5 mm up to 40 mm after injection. showed hemivertebrae of the second and third thoracic ver The infant was sedated and neither perchlorate nor stimulating tebra with partial fusion. No other anomalies were established. agents such as pentagastrin were administered prior to the At 4½mo of age the patient again developed meningitis and examination. an ampicillin-sensitive enterococcus was detected. The chest The scintigraphy revealed an increasing uptake in the sus pected cyst 5 mm to 40 mm p.i. without change of the shape ofthe scintigraphic finding (Fig. 3). ReceivedMar. 24, 1986;revisionaccepted Feb. 6, 1987. The patient later developed hydrocephalus malresorptivus For reprintscontact: Joachim Kropp, MD, Institut fürklinische causedby the meningitis.The hydrocephaluswas treated by und experimentelle Nuklearmedizin der UniversitätBonn, Sig a shunt. After recovery, the mediastinal tumor was operated. mund-Freud Stra@e25, D-5300 Bonn 1, FRG. Intraoperatively a fistula to the spine was found and was

121 8 Kropp,Emons, and Winkler TheJournalof NuclearMedicine ture. The pathogenesis is extensively described by Koes ter (2) in his comprehensive review ofthe literature and the various connections of the cysts to the CNS and GI tract by Bentley (3). These cysts develop if the noto chord and foregut failed to separate in the normal way during embryonic life. An early diagnosis is absolutely necessary because of the invariably fatal outcome without adequate treat ment—out of the 73 all 14 patients without an opera tion died—and there is an excellent prognosis after prompt surgery. There are, however, many diagnostic problems which may hamper the proper diagnosis, particularly when the cyst is ruptured. The detection of ectopic gastric mucosa using [99mTcjpertechnetatescintigraphy is well established (4- 7). The method has been used, for example, to detect FIGURE 1 gastric mucosa in Meckel's diverticulum (8) or in the Chest radiographat 4@/2mo of age shows right sided Barrett's esophagus (9). There are, however, only few thoracicalmass(arrows). reports on the detection of neurenteric cysts (10—12). With regard to the [99mTcjpertechfletatescan it has to disconnected from the vertebrae as close as possible. From the be considered that 99mTcuptake normally occurs in the lower pole of the cyst a second fistula passed just beside the salivary glands, thyroid (orthotopic or ectopic), and vena cava inferior through the diaphragm to the basis of the stomach. Pathologic uptake has been established in duodenum. After a short cut in the upper gastrointestinal neurogenic tumors (13), vascular disorders (14), and in region, the cyst and the fistulae were completely resected. hiatus herniae associated with a short esophagus (12). The histologicexamination of the cyst demonstratedthat On the other hand, one must keep in mind that only the wall consisted of gastric and foregut mucosa tissue. A two-thirds of neurenteric cysts are lined with gastric peptic ulcer was not established. mucosa. The postoperative course was free ofcomplications and the Differential diagnosis can be facilitated by adequate infant is now 1 yr old and in good health. scanning projections, sequential technique (15), and eventually by an additional use of ‘23I-scintigraphyto DISCUSSION exclude ectopic thyroid tissue. Neurentenc cysts in the definition of Neuhauser et In our case, only one projection was feasible because al. (1) are rare cases of intrathoracic masses. Only 73 of clinical condition of the patient and the confirmed cases are found sufficiently documented in the litera radiological localization of the mediastinal tumor. We

FIGURE 2 Two slidesof the CT scanshowthe rightsidedtumorinthe posteriormediastinum(arrows).

Volume28•Number7•July1987 1219 -.@ @@‘:

FIGURE 3 [@“Tc]pertechnetatescintigraphyin anteriorview shows pathologicac cumulationof the radioactivetracer in projection to the tumor (arrows). A:5 mmafterinjection.B:40 mmafter injection. A B

also did not perform ‘231-scintigraphy,as ectopic thyroid nucide meckelogram with particular reference to false tissue was very unlikely because the tumor laid in the positive results. C/in Nuc/ Med 1979; 4:285—288. posterior mediastinum. 6. Sfakianakis GN, Conway JJ. Detection of ectopic gastric mucosa in Meckel's diverticulum and in other Barrett's epithelium which normally occurs in the aberrations by scintigraphy: I. Pathophysiology and lower part of the esophagus could be excluded with a 10 year clinical experience. JNuclMed 1981; 22:647— high probability by reason ofthe shape and localization 654. of the scintigraphic finding. 7. Sfakianakis GN, Conway JJ. Detection of ectopic In conclusion, as tumors of the posterior medias gastric mucosa in Meckel's diverticulum and in other aberrations by scintigraphy: II. Indications and meth tinum associated with vertebral anomalies are sugges ods-a 10 year experience. J NucI Med 1981; 22:732— tive of neurenteric cyst it is advisable to perform se 738. @ quential scintigraphy which can 8. Berquist TH, Nolan NG, Stephens DH, et al. Specific lead to the correct diagnosis in connection with the ity of 99mTc-pertechnetate in scintigraphic diagnosis clinical history and radiologic findings. of Meckel's diverticulum: review of 100 cases. J Nuc/ Med 1976;17:465—469. 9. Gordon F, Raminez-de Gallado J, Muno ZR, et al. Diagnosis of Barrett's esophagus with radioisotopes. NOTE AmfRoentgeno/ 1974;121:716. 10. Kamoi I, Nishitani H, Oshiumi Z, et al. Intrathoracic S (Sigma 410) Technicare, Solon, OH. gastric cyst demonstrated by 99mTc-pertechnetate scintigraphy. Am J Roentgenol 1980; 134:1080—1081. 11. MacPherson RI, Reed MH, Ferguson CC. Intratho REFERENCES racic gastrogenic cysts: a cause of lethal pulmonary hemorrhage in infants. J Can Assoc Radiol 1973; 1. Neuhauser EBD, Harris GBC, Berrett A. Roentgeno 24:362—369. graphic features of neurenteric cysts. Am JRoentgenol 12. Mark R, Zoung L, Ferguson C, et al. Diagnosis of an 1958; 79:235—240. intrathoracic gastrogenic cyst using 99mTc-pertech 2. Koester B, Emons D, Kunath U, et al. Neurenterische netate.Radiology1973;109:137—138. Zyste Des Mediastinums-Falidemonstration und Lit 13. Conway JJ, Sherman JO. Evaluation of chest masses eraturubersicht. K/in Padiatr: in press. in children with early and delayed radionucide an 3. Bentley JFR, Smith JR. Developmental posterior en giography.Am JRoentgenol1970;108:575—581. teric remnants and spinal malformations. The split 14. Siddiqui A, Ryo UY Pinsky SM. Arteriovenous mal notochord syndrome. Arch Dis Childhood 1960; formation simulating Meckel's diverticulum on 35:76—86. 99mTc-pertechnetate abdominal scintigraphy. Ra 4. Chaudhuri TK, Polak JJ. Autoradiographic studies of diology1977;122:173—174. distribution in the stomach of 99m Tc-pertechnetate. 15. Duszynski DO, Anthone R. Jejunal intussusception Radiology1977;123:223—224. demonstrated by 99mTc-pertechnetate and abdomi 5. Lunia S, Luma C, Chandramouly B, et al. Radio nal scanning. Am J Roentgenol 1970; 109:729—732.

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