Meningioma in the tela choroidea of the third ventricle is rare. The purpose of this paper is to report CT and angiographic findings of this rare condition in a 40-year-old female. Precontrast horizontal section CT disclosed an isodense mass in the pineal region, compressing the posterior portion of the third ventricle. The lateral ventricles and anterior portion of the third ventricle were dilated. This isodense mass was markedly enhanced by contrast infusion. Postcontrast coronal section CT at the level of the pineal region showed a lobulated, homogeneously enhanced, high density mass between the bodies of the lateral ventricles. The mass extended to the right of the third ventricle, and compressed and shifted its upper portion to the left. Postcontrast midsagittal section CT disclosed a lobulated, homogeneously enhanced, high density mass in the posterior portion of the third ventricle just anterior to the great vein of Galen. Right carotid angiography showed that the junction of the internal cerebral and thalamostriate veins was located in the midline, but the midportion of the internal cerebral vein was displaced laterally and markedly elevated. The posterior portion of the internal cerebral vein was markedly displaced laterally. Left carotid angiography showed that the septal vein and anterior portion of the internal cerebral vein were located in the midline, but the posterior portion of this vein was markedly displaced laterally. Vertebral angiography was remarkable. The pretectal segment of the right medial posterior choroidal artery was displaced laterally and markedly antero-inferiorly, giving off a branch to the tumor. The plexal segment of this artery was displaced slightly laterally and markedly antero-inferiorly, and ran in an arcuate fashion with antero-inferior convexity in the lateral projection, indicating that this vessel runs along the antero-inferior margin of the tumor, which appeared as a homogeneous tumor stain in the late venous phase. The pretectal and plexal segments of the left medial nosterior choroidal artery were laterally and inferiorly displaced. The posterior pericallosal artery running along the outer surface of the splenium of the corpus callosum showed an almost normal configuration but a branch running along the inferior surface of the splenium of the corpus callosum was hypertrophic and slightly displaced posteriorly. Fine twigs of this artery supplied the tumor. All these findings indicated a tumor originating and developing in the tela choroidea of the third ventricle. This diagnosis was confirmed by surgery. Anatomical considerations of the tela choroidea of the third ventricle are included. CT facilitated detection of the rough location and histological features of the tumor. Carotid and vertebral angiographies were utilized in detailing the three-dimensional gross anatomical relationship between the tumor and the surrounding brain structures. Vertebral angiography also contributed to predictions of the histology of the tumor.
The growth rate of malignant gliomas was estimated by serial CT scanning. The formula for calculation of a tumor volume t days apart can be expressed as follows. Tc=log(1+GF)·t/logVB/VA Tc: cell cycle time, GF: growth fraction, VA: initial volume of the tumor, VB: the volume t days later. By applying the above formula, nine brain tumors were assessed; eight malignant gliomas and one metastatic tumor. The results show cell cycle times ranging from 5.7 days to 8.0 days, 7 days on the average. The authors developed a new system by utilizing volume changes in tumor size on CT scans, and discuss the pros and cons in great detail. Abnormally enhanced areas within the tumor appear to increase at a constant rate. Our method is based on the fact that this relevant enhanced zone can be regarded as the real volume of the tumor itself. The volume ratio obtained from two serial CT scannings on different occasions appears to be approximately equal to the real volume ratio of the tumor proper. In practice, the cell loss factor is negligible, and the growth fraction is 0.3. By using the cell cycle time calculated in this way, the growth rate of a tumor can be measured. Based upon this data, the efficacy of treatment and reappraisal of prognosis in malignant brain tumors can be judged more accurately. For example, even if tumor cells are reduced to 102 ?? 103 by combination of surgery and postoperative irradiation, it follows that in 300 to 500 days, the tumor will show up as a distinct mass lesion on CT scans, i.e. if there is no evidence of recurrence on CT scans 1.5 years after therapy, it is possible to say that a surgical cure has been achieved. We will demonstrate how our thesis applies to and is confirmed in patients with recurrent medulloblastomas.
Computerized tomography (CT) of 16 pineal region tumors including germ cell tumors arising in sites other than the pineal region was studied from the point of view of differential diagnosis and management of these tumors. They included 10 germinomas, three teratoid tumors (malignant teratoma), one teratoma, one ependymoma and one meningioma. Germinomas showed characteristic CT findings: they were noted as heterogenous and irregularly-defined masses with slightly or moderately high absorption from 20 to 30 EMI numbers (old EMI numbers) in plain scans, which were moderately enhanced in contrast scans, presenting rather well-defined masses. This CT finding was commonly noted in germinomas of the pineal and suprasellar regions as well as in germinomas invading the periventricular region or subarachnoid space. Another outstanding value offered by CT in the diagnosis of germinoma was recognition of the extremely high radiosensitivity of this tumor. Areas of high absorption except calcification in germinomas completely disappeared after chemoradiotherapy using Bleomycin, ACNU and Vincristine. Minimal radiation doses until complete disappearance of the high density lesion were mostly less than 1, 000 to 2, 000 rads. One teratoma also showed a very characteristic CT finding: a well-defined mass contained multiple, irregular calcified lesions surrounded by areas of low absorption with a wide variety of EMI numbers from minus 9 to plus 10, suggesting the presence of cysts and fatty tissue. No area of this tumor was enhanced by contrast medium except for small areas of soft tissue which showed a very slight enhancement. In three teratoid tumors, two embryonal carcinomas and one teratoblastoma, plain scans revealed isodense masses which were markedly enhanced by contrast medium. This enhancement was well-correlated with angiographical demonstration of a dense tumor stain. However, similar CT findings were noted in one ependymoma and one meningioma of the pineal region. The teratoid tumors and ependymoma were radioresistant. These observations show that germ cell tumors in the pineal region such as germinoma, teratoma, or teratoid tumors which frequently occur specifically in the Japanese population could be differentiated from each other by CT before treatment, and that a small dose irradiation could confirm the diagnosis of germinoma.
In conventional neurological grading and CT classification of hypertensive cerebral hemorrhages, the size or volume of the hematoma was often regarded as one of the prognostic factors of surgical treatment, although estimation of the hematoma volume during the operative procedure showed considerable inaccuracy. To assess the reliability of measuring hematoma volume from CT scans, a phantom study was performed. The Hounsfield Unit (H.U.) of the experimental hematoma was evaluated with respect to the partial volume phenomenon, the peripheral space phenomenon and the shadow effect of CT imaging. A plaster box containing a mixture of agar, milk and water, which was found to reproduce reasonably well the corresponding H.U. of the human head, was prepared as the experimental model, and whole blood or diluted blood was injected into the box. CT scanning was performed with EMI 1010 (120 Kv, 33 mA, 10 mm slice) and the volume of the injected blood was estimated by measuring the number of pixels, which were 10 H.U. over the H.U. of the phantom brain on the print out data. The estimation was easily programmed in a small-size additional computer and calculation of total pixels could be performed simultaneously. Deviation of the estimated hematoma volume from the injected blood volume was less than 4.9%. Forty cases of acute hypertensive putaminal hemorrhage with no evidence of intraventricular hemorrhage were examined and the volume of the hematoma was calculated. Almost all of the CT scans were performed within 3 days after the hemorrhage. The H.U. of the putaminal region of the contralateral side was used as a standard value, which was found to be 35 H.U. on the average and the extent of the hematoma was thus determined from the area of 45 H.U. or more. The hematoma volume estimated by CT was significantly less than those in previous reports which were estimated by surgical evacuation. However, it showed remarkable correlation with the neurological grading of Kanaya. The average amount of the hematoma was 10 ml in grade 1, 20 ml in grade 2, 40 ml in grade 3, 60 ml in grade 4a, and 90 ml in grade 4b and grade 5. Furthermore, there was a significant relationship between ADL scores in the follow-up study and the estimated hematoma volume. In cases with a Kanaya CT classification of III a or IV a or cases with the high density area extending into the corona radiata, the ADL score did not reach one or two in the follow-up study, unless the hematoma was less than 30 ml. When the hematoma volume was estimated to be more than 65 ml, there were no cases of survival.
Thirteen cases of medulloblastoma were experienced. All of the patients were operated on and the diagnosis was confirmed histologically. Nine were then treated with cranial and spinal irradiation. Three patients received incomplete irradiation and one died without it. A one year-old and a 14 year-old boys among the nine patients with completed scheduled irradiation showed no recurrence or metastasis; the former for seven years and four months and the latter for five years. In the other seven cases, five had local recurrences and six had spinal metastasis. Four of these patients also showed second recurrences and/or metastasis. There were three spinal, one frontal, one extracranial metastases and two local recurrences. Recurrences and/or metastases in three of these seven cases were aggressively treated with re-irradiation and combined-chemotherapy (vincristine, procarbazine and predonisolone, including methtrexate occasionally). Patients with recurrence and/or metastasis after one year or with survival times of more than three years were found to be older, had radical operations and received less primary dosis in the posterior fossa and a higher dosis in the spinal canal, compared with patients with early recurrence and/or metastasis or with short survival periods. Three patients who received re-irradiation and combined chemotherapy and one patient who was treated with antibiotics for meningitis are alive at present. It was clear that not only the age of patients and operative procedures, but the spinal irradiation dosis influenced the time of recurrence or metastasis and survival. Primary spinal irradiation doses were below 2, 500 rads in seven of the nine cases who completed initial cranial and scheduled spinal irradiation. It seems that a low dosis in the spinal canal decreased the survival rate compared with those in other institutions using higher spinal doses. Complete irradiation of the entire CNS at certain doses (whole brain: 4, 000-5, 000 rads, posterior fossa: 4, 500-5, 000 rads, and spinal: 3, 000-3, 500 rads) and early postoperative chemotherapy are recommended, and aggressive treatment including re-operation, re-irradiation and long term combined-chemotherapy is indispensable to combat recurrence and metastasis.
The authors report 12 cases of prolactin-secreting pituitary microadenomas and discuss the neuroradiological diagnosis and endocrinological evaluations. The patients were all females between 28 and 38 years of age. Eleven cases sustained amenorrhea or oligomenorrhea with galactorrhea and one case sustained only amenorrhea. Four cases had already experienced delivery and the symptoms had continued since the last delivery in three cases. Transsphenoidal surgery confirmed the size of the tumor within 10 mm in diameter. Plain radiograms of the sella turcica showed a normal sellar area and sellar volume but indicated two cases with a double floor of the sella and one case with localized ballooning along the anteroinferior portion of the sella. Hypocycloidal tomograms at 2 mm intervals in the lateral view showed localized `expansion' with `cortical thinning' along the sellar floor in all cases. The findings were located at the anteroinferior portion of the sella in nine cases and at the inferior or posteroinferior portion in three cases. Hypocycloidal tomograms in the AP view, however, showed abnormalities of the sellar floor in only four cases. Conventional CT scans with contrast could not definitely delineate microadenomas. The wide width `bone window CT scan' showed localized expansion of the central portion of the sella in two cases, diffuse expansion of the sella in one case and localized lateral expansion of the sella in one case. Subtraction magnification angiograms were normal and pneumoencephalotomograms did not demonstrate suprasellar extension of the tumors. Results of the endocrinological examinations were compared with those of prolactin-secreting pituitary macroadenomas. The basal serum PRL levels tended to be higher in macroadenomas but no clear separation could be made between the two groups. Retarded response of serum PRL to TRH was observed in a single case of microadenoma but not in cases of macroadenomas. Diurnal changes of serum PRL were absent both in microadenomas and macroadenomas. The L-dopa suppression effect on serum PRL was observed in nine out of 11 microadenomas and four out of five macroadenomas. The Bromocriptine suppression effect on serum PRL was observed in about half of both groups. The L-dopa stimulation effect on serum HGH was normal in six out of ten microadenomas and one out of five macroadenomas. The insulin tolerance test on serum HGH was normal in four out of five microadenomas and subnormal in both macroadenomas. The HGH reserve was subnormal in five out of 12 microadenomas and four out of five macroadenomas. The LH and FSH reserves for LH-RH were impaired in three and one case respectively out of 11 microadenomas and were greatly impaired (three out of six and two out of five respectively) in macroadenoma cases. The TSH and ACTH reserves were rarely impaired both in microadenomas and macroadenomas. In conclusion, hypocycloidal tomograms in the lateral view proved very valuable in the detection of microadenomas. In the endocrinological examinations, the PRL and HGH reserves were impaired but the TSH, LH, FSH and ACTH reserves were only slightly impaired in microadenomas. In macroadenomas, however, the LH and FSH reserves were also impaired.
Among 150 cases of transsphenoidal pituitary operations performed at the Evanston Hospital, Evanston, Illinois, 84 cases were carefully reviewed prospectively or restrospectively in the light of postoperative patterns ofwater-sodium metabolism. Postoperative diabetes inspidus was observed more remarkably in hypophysectomized patients. Among these patients with severe postoperative diabetes inspidus, there was a significantly high rate of pituitary metastasis of breast cancer in the pathological findings of the hypophysectomized gland. In grade III diabetes inspidus (continuing over a month), 62.5% of the patients showed this finding. The postoperative pattern of sodium metabolism was complicated. Fifty out of 58 cases had remarkably decreased natriuresis in the first 3 or 4 postoperative days demonstrating a sudden drop of urine osmolarity followed by increased serum osmolarity with or without polyuria. Among these patients, 26 cases returned to normal in the next two weeks. However, eight had continuous diabetes inspidus with or without hypernatremia, three showed possible “essential hypernatremia”, nine had S.I.A.D.H. and two were diagnosed as overhydration. Sodium regulation should be considered independently from water metabolism in certain patients. In many examples, hypo or hyper-natremia is not associated with abnormal water metabolism. It was emphasized that monitoring the daily osmolarity of serum and urine as well as serum sodium level is very important in post transsphenoidal pituitary operative care.