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415

Pineal Region Tumors: Computed Tomographic-Pathologic Spectrum

Nancy N. Futrell' While several computed tomographic (CT) studies of posterior third ventricular Anne G. Osborn' have included descriptions of pineal tumors, few reports have concentrated Bruce D. Cheson 2 on these uncommon lesions. Some authors have asserted that the CT appearance of many pineal tumors is virtually pathognomonic. A series of nine biopsy-proved and eight other presumed tumors is presented that illustrates their remarkable heterogeneity in both histopathologic and CT appearance. These tumors included , teratocarcinomas, hamartomas, and other varieties. They had variable margination, attenuation, calcification, and suprasellar extension. Germinomas have the best response to . Biopsy of pineal region tumors is now feasible and is recommended for treatment planning.

Tumors of the pineal region account for less th an 2% of all intracrani al neoplasms [1]. While several reports of computed tomography (CT) of third ventricular neoplasms have in cluded an occasi onal pineal tumor [2 , 3], few have focused on the radiographic spectrum of th ese uncommon lesions [4]. Some authors have asserted that the CT appearance of many pineal tumors is virtuall y pathognomonic [5]. We studied a series of nine biopsy-proven pineal gland tumors that demonstrated remarkable heterogeneity in both histopath ologic and CT appearance.

Materials and Methods

A total of 17 pineal gland tumors were detected in 15,000 consecutive CT scans. Four patients were female and 13 were male. Mean age for the fe males was 27 years; for the males, 15 years. Initial symptoms ranged from , nausea, and , to Parinaud syndrome, vi sual field defects, , and hypopituitari sm (table 1). Pl ain and contrast-enhanced CT scans were obtained in all cases. Nine of the 17 cases were proven by biopsy or autopsy. Two were germinomas (atypical ), two were teratocarcinomas, and one each was pineal hamartoma, benign Received October 2 1, 1980 ; accepted after revision March 23, 1981 . , , and neurilemmoma. One other case was designated as a " mali gnant pineal tumor" by cerebrospinal fluid cytology. One case had insufficient tissue for patho­ Presented at th e annual meetin g of the Ameri­ can Roentgen Ray Society, San Francisco, CA, logic diagnosis. One case was diag nosed as a pineal lipoma from characteri stic CT findings. March 1981. The dramati c response of fi ve other cases to radiation therapy led to the presumptive clinical diagnosiS of (table 1); these had no evidence of residual or recurren t 1 Departm ent of Radiology, University of Utah College of Medicin e, 50 N. Medical Dr. , Salt Lake disease for a minimum of 3 years. One pati en t was lost to foll ow-up. City, UT 84132. Address reprint requests to A. G. Osborn .

2 Department of Medicine, University of Utah Results Coll ege of Medicine, Salt Lake City, UT 84132. This article appears in September/ October Germinoma (Atypical Teratoma) 1981 AJNR and November 198' AJR. The two documented and five presumed germ inomas were either isodense or AJNR 415-420, September/ October 1981 0195- 6 108/ 81 / 020 5 - 0415 $00.00 slightly hyperdense on plain CT scan (fig. 1 A) and showed marked, uniform © American Roentgen Ray Society increase in attentuation after contrast enhancement (fig. 18 ). Several were well 4 16 FUTRELL ET AL. AJNR:2, September / October 1981

TABLE 1: Pineal Gland Tumors: Case Summaries

Case Ag e. Presenting Symptoms CT Appearance Biopsy Treatment/ Results No. Gend er 6, M Diplopi a, headache, nau- Isodense noncalcified Germinoma Complete resolution foll ow- sea, vomiting, CN III , posterior third ventricu- ing ventricular shunting, IV palsies lar mass, irregular mar- surgery, and radiation gins, inhomogeneous therapy contrast enhancement 2 .... 17, M Anorexia, diabetes insip- Well margin ated, hyper- Atypical teratoma with Died 2 years after initial idus, panhypopituitar- dense mass left basal prominent germinoma- presentation; atypi cal ter- ism ganglia with strong tous elements (au- atoma with suprasellar, contrast enhancement, topsy) pineal, basal ganglia, edema, obstructive hy- ependymal involvement droceph alus secondary diagnosed at postmortem to aqueduct stenosis; subtle ependymal en- hancement, third ven- tricle 3 18, M Vomiting, diabetes insip- Well delineated hyper- Complete resolution after idus, Parinaud syn- dense suprasellar, pos- ventricular shunt and ra- drome, panhypopitui- teri or third ventricular diation therapy; no recur- tarism masses; Ca++ in pineal rence after 4 years; pre- region. Strong contrast sumptive diagnosis: ger- enhancement of minoma masses and ventricular ; obstructive 4 .. 14 , F Headache, diplopia, pap- Well delineated slightly Ventricular shunt, radiati on illedema, seizu res hyperdense posterior therapy with tumor reso- third ventri cular mass lution; 1 year follow-up; without Ca++ ; strong, presumptive diagnosis: uniform contrast en- germinoma hancement; moderate obstructive hydroceph- alus 5 . 26, M Headache, vomiting, an- Calcified isodense poste- Complete resolution after orexia ri or third ventricular ventri cular shunting and mass with moderate radiation therapy; no re- contrast enhancement, currence after 5 years; obstruc ti ve hydroceph- presumpti ve diagnosis: alu s germinoma 6 . ... 17, M Headache, Parinaud syn- Isodene third ventricular Complete resolution after drome, papilledema mass with strong con- ventricular shunting and trast enhancement radiation th erapy; 3 year follow-up without recur- rence; presumptive diag- nosis: germinoma 7 .... 14, M ?Headache, Parinaud Well marginated hyper- Complete resolution after syndrome dense pineal region tu- ventricular shunting and mor with focal calcifi- radiation therapy; no re- cation, strong contrast currence after 5 years; enhancement, moder- presumed germinoma ate obstructive hydro- cephalus 8 .. 14 , M Headache, nausea, vom- Well delinated isodense, Teratocarcinoma Di ed from widespread iting, diabetes insip- calcified posterior third metastatic disease 1 year idus, Parinaud syn- ventricular mass with after diagnosis drome strong contrast en- hancement, moderate obstructive hydroceph- alus 9 18,M Diabetes insipidus, pan- Lobulated, hyperdense Teratocarcinoma Apparent resolution of both hypopitu itarism suprasellar, posteri or masses foll owing shunt th ird ventri c ular and radiation therapy; re- masses with foci of cal- currence of suprasellar cification in the pineal component after 6 tumor; strong but months; alpha-fetoprotein sli ghtly inhomogeneous in CSF contrast enhancement AJNR:2, September/ October 1981 PINEAL REGION TUMORS 417

Case Ag e. Presenting Symptoms CT Appearance Biopsy Treatment / Results No. Gender 10 6, M Anisocoria, Parinaud Well marginated posterior Pineal hamatoma Shunted with surgical re- syndrome discovered third ventricular mass moval; in coma 4 months after head trauma with densely calcified postop with major resid- rim, contrast-enhanc- ual neurologic defic its ing center; moderate 2'/4 years later hydrocephalus 11 8, M Decreased coordination Multicystic lobulated, ir- Benign teratoma (with Residual mass and neuro- regular third ventricular abundant neurogli al logic deficit following sur- tumor with foci of calci- elements) gery (3 year follow-up) fication, patchy periph- eral contrast enhance- ment 12 ... 63, M Memory loss, imbalance Well marginated isodense Neurilemmoma or pineo- Complete surgical removal partially calcified pos- cytoma with predomi- terior third ventricular nately neural el ements mass with moderate obstructive hydroceph- alus; uniform contrast enhancement 13 .... 33, M Dizziness, headache Slight irregular hyper- astrocytoma Unsuccessful radiation dense posterior third therapy; died 1 year fol- ventricular mass with lowing biopsy focal calcification, patchy contrast en- hancement 14 .. .42, F Headache, vomiting Well delineated low at- Presumed lipoma because tenuation (-15 H) of CT characteristics mass with peripheral calcification; no con- trast enhancement; no hydrocephalus 15 .. 14, M Anorexia, nausea, vomit- Slightly irregular enhanc- " Small malignant cells" Complete resolution follow- ing, diabetes insipidus ing, partially calcified on CSF cytology ing ventricular shunting, posterior third ventricu- radiation therapy (16 lar mass; subtle supra- month follow-up) sellar mass identified on multiple thin , over- lapping axial scans; moderate obstructive hydrocephalus 16 .... 20, M Diplopia, Parinaud syn- Well demarcated hyper- In sufficient tissue Resolving after radiation drome dense posterior third therapy (2 month follow- ventricular mass, small up only) focus of Ca++ ; strong contrast enhancement 17 .... 22, M Diplopia, Parinaud syn- Irregular mixed density Lost to follow-up drome posterior third ventricu- lar mass with foci of calcification, patchy contrast enhancement

Note.-eN = cranial nerve, CSF = cerebrospinal fluid. postop = postoperati ve .

marginated while others appeared less well circumscribed. similar case of documented " ectopic " in the Four cases had definite suprasellar involvement (fig . 2A). basal ganglia has been reported [6]. The present case was The suprasellar mass was quite subtle in two cases and diagnosed at autopsy. required several overlapping thin sections for detection. One case demonstrated striking subependymal enhance­ ment (fig . 28). When present, calcification appeared limited Teratocarcinoma to the pineal gland, which was itself engulfed by the tumor. One case had a well demarcated, partly calcified, solitary An atypical teratoma with prominent germinomatous ele­ posterior third ventricular mass that was slightly hyperdense ments was seen as a hyperdense mass in the basal ganglia on un enhanced CT scans. The lesion showed striking ho­ with strong contrast enhancement and ependymal spread mogeneous increase in attenuation with contrast infusion along the third ventricle (fig . 3). To our knowledge, only one (fig. 4). Although the CT appearance initially suggested 418 FUTRELL ET AL. AJNR:2, September/ October 1981

A B A B Fig. 1.-Case 4, presumed pineal germinoma. A, Plain scan. Slightly Fig. 3.-Case 2, atypical teratoma with germinomatous elements. A, hyperdense, posterior third ventricular mass (arrows ). B, After intravenous Without contrast. Hyperdense mass with peripheral edema in basal ganglia contrast infusion. Marked in crease in attenuation of mass (arrows). (arrows). B, Marked increase in attenuation of lesion after contrast enhance­ ment. Subtle ependymal involvement (arrows ). At autopsy, pineal gland and ventricular ependyma were diffusely involved.

enhancement; one small focus of calcification was present (fig. 7).

Pineal Parenchymal Neoplasms One hyperdense posterior third ventricular mass with strong contrast enhancement was either a neurilemmoma or with predominant neural elements (fig. 8).

Astrocytoma

One lobulated contrast-enhancing pineal region mass was found to be an astrocytoma at autopsy (fig. 9). It probably originated in the midbrain. A B Fig . 2. -Case 3, presumed pineal germinoma. Contrast-enhanced scans with suprasellar (A, arrows) and diffuse ependymal (B, arrows ) involvement. Lipoma

One homogeneous (-1 5 Hounsfield units [H) noncon­ pineal germinoma, teratocarcinoma was found at surgery. trast-enhancing lesion with a thin peripheral rim was identi­ A second case had lobulated hyperdense suprasellar and fied in the pineal region. The CT characteristics were typical posterior third ventricular masses with scattered calcific for lipoma. foci. Strong but slightly inhomogeneous contrast enhance­ ment was present (fig. 5). Complete resolution of these lesions after rad iation therapy led to the presumptive diag­ Discussion nosis of germinoma. The suprasellar component recurred The term " pinealoma" has been loosely applied to all after 6 months. Biopsy disclosed a teratocarcinoma. tumors arising from the pineal gland and posterior third ventricle. This practice has resulted in significant confusion Pineal Hamartoma in classifying the several varieties of tumors that arise from the pineal body. The single pineal hamartoma had a striking peripheral Tumors arising from pineal parenchymal cells (" true pi­ calcified rim with a hyperdense center that enhanced after nealomas" ) are much less common than germ cell neo­ intravenous contrast administration (fig. 6). plasms (germinomas, teratomas, endodermal sinus tumors, or the rare primary intracranial choriocarcinoma) [7-9]. Parenchymal tumors have been subdivided into a more Benign Teratoma undifferentiated type composed primarily of immature cells A large irregular, locally invasive lesion with mixed low (the so-call ed " pineoblastoma" is histologically similar to and normal attenuation regions showed patchy contrast ) and pineocytoma with more mature com- AJN R:2, September I October 1981 PINEAL REGION TUMORS 419

A B Fig. 4 .-Case 8, teratocarcinoma. Fig. 5. - Teratocarcinoma. A, Case 9 , before contrasl enhancement. Lobulated hyperdense lesions in suprasell ar Contrast-enhanced scan. Well deline­ region and posterior third ventricle (arrows ). Punctate calcific ations within pineal mass. Subarachnoid air from ated enhancing mass in third ventricle previous pneumoencephalography attempted elsewhere. 6, Case 11 , contrast-enh anced CT angiotomogram. (arrows ). Plain scans (not shown) Computer-registrered stereoscopic pair can be focused with either mechanicat viewer or c ross-eyed stereo demonstrated an isodense, partly cal­ techniques. cified pineal region mass.

A B A B Fig . 6. -Case 10, pineal hamartoma ( arrows ). Pl ain (A) and contrast­ Fig. 7.-Case 11 , benign teratoma. Plain (A) and contrast-enhanced (6) enhanced (6) sc ans. Peripheral rim of calcification along with central en­ scans. Locally in vasive, lobulated , mixed attenuation mass with irregular hancement of hyperdense mass. There is moderate obstruc tive hydroceph­ areas of contrast enhancement. Solitary focus of calcificati on (arrow). alu s. ponents. The latter can have either predominant astrocytic well delineated, uniformly enhancing lesion was a teratocar­ or neuroepithelial differentiation [10). cinoma (fig. 4), while a mi xed density, locally invasive mass The remarkably divergent differentiating potential of pin­ was histologically benign (fig . 7). Therefore, we found no eal parenchymal tumors plus the considerable heterogeneity definite correlation between CT appearance and tumor type. of germ cell neoplasms is reflected in their variable CT While some authors have regarded periventricular con­ appearance. While calcification in pineal neoplasms sug­ trast enhancement as virtually pathognomonic of germinoma gests teratoma, it can also occasionally occur in pineal [5], diffuse ventricular spread or invasion of the midbrain or parenchymal tumors [4, 11). Although ependymal or supra­ basal ganglia can also occur with pineobl astoma or malig­ se ll ar involvement has been considered diagnostic of ger­ nant teratoma [10). One atypical teratoma with numerous minoma [5], teratocarcinoma can be radiographically indis­ germinomatous components was eccentrically located in tinguishable (fig. 5), We found that a presumptive histologic the basal ganglia and at autopsy had marked ependymal diagnosis on the basis of CT alone was not possible. Uni­ and suprasellar involvement (fig. 3). form ity or intensity of contrast enhancement, size, tumor The term " ectopic pinealoma" has been used in accur­ margination, multiplicity, and location also were not helpful ately to designate suprasellar germinoma [12]; embryoni c in distinguishing benign from malignant neoplasms. One nests of true pineal tissue have not been demonstrated in 420 FUTRELL ET AL. AJNR:2, September j October 1981

[9, 15, 18, 21). The great variations in and clinical behavior of our 17 pineal region neoplasms persuade us also that the traditional approach of treatment without a tissue diagnosis is no longer warranted.

REFERENCES

1. Koos WT, Miller MH. Intracranial tumors of infants and children. St. Louis: Mosby, 1971 2. Straud RD, Baker RA, Ordia IJ , Arkins T J. Metrizamide ventric­ ulography and computed tomography in lesions about the third ventricle. Radiology 1978;128: 405-41 0 3 . Messina AV, Potts DG, Sigel RM, Liebeskind AL. Computed tomography: evaluation of the posterior third ventricle. Radiol­ ogy 1976;119: 581-592 4. Zimmerman RA, Bilaniuk L T, Wood JH, Bruce DA, Schut L. 8 9 Computed tomography of pineal, parapineal, and histologically Fig. 8 .-Case 12, neurilemmoma or pineocytoma. Contrast-enhanced related tumors. Radiology 1980; 137: 669-677 scan. Enhancing posterior third ventricular mass. 5. Dupont MG, Gerard JM, Flament-Durond J, Baleriaux-Waha 0, Fig. 9 .-Case 13 , astrocytoma. Contrast-enhanced scan of pineal tumor Mortelmans LL. Pathognomonic aspect of germinoma on CT ( arrows ). scan. Neuroradiology 1977;14:209-211 6. Numaguchi Y, Kishikawa T, Ideda J, et al. Prolonged injection this region [13). These tumors may occur either as isolated angiography for diagnosing intracranial neoplasms. Radiology suprasell ar masses or in association with a similar pineal 1980;136:387-393 region tumor (fig. 3) [14). Four of five patients with presumed 7. Rubinstein LJ. Tumors of the . In : Atlas pineal germinoma also had a suprasellar lesion; all five were of tumor pathology, 2d series, fasc 6. Washington DC: Armed seen initially with diabetes insipidus. One pineal teratocar­ Forces Institute of Pathology, 1972:269-283 cinoma also was associated with a suprasellar mass. From 8. Tavcar 0, Robboy SJ , Chapman P. Endodermal sinus tumor of this experience, we believe exhaustive search for a supra­ the pineal region. Cancer 1980;45:2646-2651 sellar mass is imperative in all pineal region tumors. Multi­ 9 . Kawakami Y, Yamada 0, Tabuchi K, et al. Primary intracranial planar CT with thin, overlapping cuts or metrizamide CT choriocarcinoma. J Neurosurg 1980;63 :369-374 10. Herrick MK, Rubinstein LJ. The cytological differentiating po­ cisternography is helpful since the suprasellar component tential of pineal parenchymal neoplasms (true ). may be quite small. Brain 1979; 102: 289-320 Other posterior third ventricular or parapineal masses can 11 . Lin SA, Crane MD, Lin ZS, et al. Characteristics of calcification be virtually indistinguishable from pineal tumors on CT. in tumors of the pineal gland. Radiology 1978;126: 721-726 Exophytic brainstem , neurilemmoma, incisural men­ 12. Rubin P, Kramer S. Ectopic pinealoma: a radiocurable neu­ ingioma, intraventricular , and metas­ roendocrinologic entity. Radiology 1965;84: 521-523 tasis should be included in the differential diagnosis of 13. Sung 01, Harisiadis L, Chang CH. Midline pineal tumors and enhancing masses in or adjacent to the posterior third suprasellar germinomas: highly curable by irradiation. Radiol­ ventricle or quadrigeminal plate. Since histology cannot be ogy 1978;128 :745-751 inferred from the CT appearance alone, diagnostic efforts 14. Swischuk LE, Bryan RN. Double midline intracranial atypical teratomas. AJR 1974;122: 517 -524 should be focused on accurately delineating the tumor itself, 15. DeGirolami U, Schmidek H. Clinicopathological study of 53 detecting suprasellar or ependymal involvement, and ex­ tumors of the pineal region. J Neurosurg 1973;39: 455-462 cluding primary vascular lesions that can mimic pineal re­ 16. Brady LW. The role of radiation therapy. In: Schmidek HH, ed. gion neoplasms. Pineal tumors. New York: Masson, 1977: 127 -132 Before 1970, histologic verification of pineal tumors was 17. Obrador S, Soto M, Gutierrez-Diaz JA. Surgical management seldom possible due to their deep midline location [13). of tumors of the pineal region. Acta Neurochir (Wien) 1976;34: Mortality was unacceptably high, approaching 60% for sur­ 159-171 gical removal and 33% for biopsy alone [15). Ventricular 18. Neuwelt EA, Glasberg M, Freukel E, Clark WK. Malignant shunting and radiation therapy without pathologic diagnosis pineal region tumors: a clinico-pathological study. J Neurosurg were common since an estimated 70% of pineal region 1979;51 : 597 -607 tumors are radiosensitive [16). With more sophisticated 19. Brown RA. A computerized tomography-computer graphics approach to stereotaxic localization. J Neurosurg 1979;51 : microsurgical techniques [15], operative morbidity and mor­ 715-720 tality have declined [17, 18). Accurate CT-guided stereo­ 20. Brown RA, Roberts TS, Osborn AG: Stereotaxic frame and taxic biopsy procedures also may enhance treatment plan­ computer software for CT -directed neurosurgical localization. ning [19, 20). An increasing number of investigators believe Invest Radio/1980;15 :308-312 that tissue diagnosis is now both practical and necessary 21 . Chapman PH, Linggood RM. The management of pineal area for determining the most appropriate therapeutic regimen tumors: a recent reappraisal. Cancer 1980;46: 1253-1 257