Unusual extra-axial central nervous system involvement of non-Hodgkin's lymphoma: magnetic resonance imaging

The MR imaging findings in a patient with non-Hodgkin's lymphoma with unusual involvement of the sella, pituitary stalk and left parasellar region are reported here. On the basis of the MR imaging findings, the initial differential diagnosis included invasive pituitary adenoma, a granulomatous lesion and en plaque meningioma. Trans-sphenoidal biopsy of the sellar mass showed chronic inflammatory changes and the patient was initially treated for tuberculosis. Because follow-up imaging showed the lesion to be progressive, a biopsy was done of an enlarged right inguinal lymph node. This revealed non-Hodgkin's lymphoma.     

Enlargement of the proximal pituitary stalk associated with spontaneous recovery from multiple pituitary hormone deficiencies

We report the case of a child with multiple pituitary hormone deficiencies and a truncated pituitary stalk on MR imaging who had recovery of normal secretion of pituitary hormones in early adulthood. Follow-up MR imaging examination after recovery revealed marked enlargement of the proximal pituitary stalk. The case of our patient helps to explain the mechanism whereby some patients experience recovery of hormonal function.     

Osteoma of the inner table of the skull--CT diagnosis

AIM: The purpose of this study was to ascertain CT criteria for the differentiation of osteoma of the internal table of the skull (OIT) from meningioma.MATERIAL AND METHODS: Thirty-eight patients with proven OIT by operation or by post-mortem examination and 100 patients with proven meningioma were studied.RESULTS: Unenhanced computed tomography (UCT) and enhanced CT (ECT) was performed in each case and images on brain and bone window settings were evaluated. Measurements were taken of the widest and narrowest diameters of the OIT on the bone window images. The OIT appeared as an ivory-density, mushroom-like mass with well-defined borders attached to the inner table of the skull by a bony stalk or neck. The ratio between the widest diameter of the mass and the narrowest area of the stalk or neck ranged from 1.6 to 6. The CT features of 100 meningiomas were not consistent with OIT, using the following parameters: contrast enhancement, surrounding vasogenic oedema, dural lucent line, osteolytic bone lesion and cystic component. Hard meningiomas without contrast enhancement did not present with a bony stalk or neck. No meningioma had the CT features of OIT, and no OIT had the CT features of meningioma. No patient operated on for OIT showed any clinical improvement following surgery.CONCLUSIONS: Computed tomography examination can be sufficient for the diagnosis of OIT and may therefore prevent unnecessary surgery.Avrahami, E., Even, I. (2000). Clinical Radiology55, 435-438.     

Correlation of high signal intensity of the pituitary stalk in macroadenoma and postoperative diabetes insipidus

BACKGROUND AND PURPOSE: High signal intensity (HSI) at the pituitary stalk is reported in pituitary adenomas. Our purpose was to clarify how and when this HSI formed, its long-term fate, and its relation to the function of infundibuloneurohypophyseal (INH) system. METHODS: Twenty-two patients with pituitary adenoma and supradiaphragmatic extension underwent 1.5-T MR imaging. Patients were assigned to two groups A (n = 18; those with stalk tip HSI) and B (n = 4; those without HSI) on postoperative T1-weighted images. Endocrine status was postoperatively evaluated and compared in both groups. RESULTS: Group A patients did not have postoperative permanent diabetes insipidus (DI). Preoperative images in 17 patients revealed linear or ovoid HSI on the adenoma surface immediately above the diaphragma sellae. Of these, two with a poorly developed diaphragma sellae had HSI near the median eminence and inside the sella turcica. HSI was not apparent in the remaining patient with a giant, irregularly shaped adenoma. In group B, three patients had permanent DI. No patient had HSI on preoperative images. CONCLUSION: Postoperative pituitary stalk HSI is derived from preoperative supradiaphragmatic HSI on the adenoma surface. The suspected mechanism is blockage of the hypophyseal-pituitary axis, with an accumulation of neurosecretory granules at the diaphragmatic level. Diaphragmatic shape may influence the location of HSI. The shape and location of HSI are essentially stable for years after surgery. No patients with permanent DI had HSI before or after surgery. HIS at the pituitary stalk tip is a useful landmark for predicting functional integrity of the INH system in patients with a large pituitary adenoma.     

Case report: CT demonstration of pituitary stalk relapse in childhood acute lymphoblastic leukaemia

Central nervous system relapse in childhood acute lymphoblastic leukaemia (ALL) occurs in 8% (all risks). Leptomeningeal infiltration is the usual form of relapse and pituitary stalk involvement is rarely found. We report the CT demonstration of pituitary stalk relapse with endocrine evidence of disruption of the hypothalamo-pituitary axis.     

Neuroimaging findings in a suprasellar granular cell tumor

A 27-year-old woman presented with a history of amenorrhea, visual disturbance, and diabetes insipidus. Magnetic resonance imaging showed a large enhancing suprasellar mass with associated edema involving the left striatum. The lesion was hypometabolic on fluorodeoxyglucose-positron emission tomography. At surgery, a subtotal resection of a vascular tumor that appeared to arise from the posterior pituitary and hypothalamus was carried out. Pathologic examination revealed a granular cell tumor. We report the preoperative neuroimaging findings in this rare posterior pituitary stalk tumor.     

High signal intensity of the infundibular stalk on fluid-attenuated inversion recovery MR.

PURPOSETo determine the MR imaging characteristics of the pituitary stalk with a fluid-attenuated inversion recovery (FLAIR) technique.METHODSWe retrospectively studied the prevalence of a high-signal infundibular stalk on FLAIR MR images of the brain in 133 patients and compared this finding with the patients'' ages. To understand the cause of the high signal intensity of the pituitary stalk on FLAIR images, we calculated the T1, T2, and proton-density values in regions of gray matter, white matter, and the pituitary stalk in nine cases.RESULTSFLAIR images showed the pituitary stalk as having high signal intensity in 97 (73%) of 133 cases; however, in 11 of 16 patients less than 10 years old, the infundibular stalk was not of high signal intensity. In patients with a high-signal pituitary stalk on FLAIR images, the T2 value of the pituitary stalk was longer than that of gray or white matter.CONCLUSIONHigh signal intensity of the infundibular stalk was frequently seen on FLAIR MR images of the brain at all ages. A prolonged T2 value of the pituitary stalk caused the high signal intensity, presumably reflecting the fluid component of the pituitary stalk.     

MR Imaging of Central Diabetes Insipidus: A Pictorial Essay

Central diabetes insipidus (DI) can be the outcome of a number of diseases that affect the hypothalamic-neurohypophyseal axis. The causes of the condition can be classified as traumatic, inflammatory, or neoplastic. Traumatic causes include postoperative sella or transection of the pituitary stalk, while infectious or inflammatory causes include meningitis, lymphocytic hypophysitis, and granulomatous inflammations such as sarcoidosis and Wegener''s granulomatosis. Various neoplastic conditions such as germinoma, Langerhans cell histiocytosis, metastasis, leukemic infiltration, lymphoma, teratoma, pituitary adenoma, craniopharyngioma, Rathke cleft cyst, hypothalamic glioma, and meningioma are also causes of central DI. In affected patients, careful analysis of these MR imaging features and correlation with the clinical manifestations can allow a more specific diagnosis, which is essential for treatment.     

Partial duplication of the hypophysis in adult patients: report of 2 cases

Complete duplication of the pituitary gland is an extremely rare condition which is associated with a wide range of anomalies. An incomplete duplication affecting only the anterior pituitary gland or the pituitary stalk has not been described so far. We report 2 such cases of partial duplication of the hypophysis and briefly review the literature.     

颅内多发原发性肿瘤的CT与MRI诊断

目的：报道１５例颅内多发原发性肿瘤的ＣＴ和ＭＲＩ表现，并评价ＣＴ与ＭＲＩ的诊断价值。方法：１５例颅内多发原发性肿瘤均行ＣＴ检查，其中４例行ＭＲＩ检查，均经手术病理证实。结果：多发胶质瘤４例，其中恶性室宫膜瘤３例，表现为脑室内及额顶叶脑实质内实质性肿块或囊性病变，多发星形细胞瘤１例，病变分别位于额叶及小脑蚓部；双侧听神经瘤及多发脑膜瘤各３例、ＣＴ和ＭＲＩ表现均较典型；脑膜瘤合并胶质瘤３例、脑膜瘤合并听神经瘤１例和垂体瘤合并胶质瘤１例。结论：结合肿瘤的ＣＴ和ＭＲＩ表现特点，可对大多数颅内多发原发性肿瘤作出正确诊断，ＭＲＩ对脑膜瘤的诊断优于ＣＴ。     

Isolated intracranial Rosai-Dorfman disease mimicking meningioma in a child: a case report and review of the literature

We report the first case of extensive involvement of isolated intracranial Rosai-Dorfman's disease (RDD) in a child. Our case is unique because it presents with involvement of the middle cranial fossa, cavernous sinus, pituitary gland, orbit, ethmoid and sphenoid sinuses. Previous cases of intracranial RDD in children have reported separate involvement of cavernous sinus, suprasellar region, and frontal and petroclival regions. Involvement of the pituitary gland has so far not been reported. A 14-year-old male presented with a medical history of loss of vision, raised erythrocyte sedimentation rate (ESR), and abnormal prolactin and cortisol levels. Radiologically the diagnosis was meningioma. The histopathological diagnosis was RDD with emperipolesis and S-100 positivity. RDD is a histiocytic proliferation of unknown aetiology, which commonly affects lymph nodes. Uncommonly it involves the extranodal sites and rarely the central nervous system (CNS). 80 cases of RDD involving CNS have been reported in the literature, and only 5 were in children. Although the definitive diagnosis of RDD disease is based on the histopathology report, it should be included in the differentials of a lesion mimicking meningioma especially in children.     

CT of the normal pituitary stalk

A prospective study assessed the size and frequency of visualization of the normal pituitary stalk on high-resolution computed tomography (CT). The normal pituitary stalk can be seen on the vast majority of high-resolution scans obtained with thin sections and intravenous contrast material. The upper size limit of the normal pituitary stalk is 4 mm at the level of the dorsum sellae and 4.5 mm above the dorsum. Stalks larger than this should be viewed with suspicion. Comparison of the size of the pituitary stalk with that of the nearby basilar artery is possible on most CT scans, providing a convenient and reliable visual check of the size of the stalk.     

Pure Intrasellar Meningioma Located Under the Pituitary Gland: Case Report

Most intrasellar meningiomas are located in the subdiaphragmatic and supraglandular region because they originate from the diaphragma sellae. Subglandular meningiomas located under the pituitary gland are extremely rare. Intrasellar meningiomas in the subdiaphragmatic and subglandular region probably originate from the dura in the sellar floor. We report a case of a subglandular meningioma along with a review of the literature.     

Magnetic resonance imaging in patients with panhypopituitarism

Primary panhypopituitarism consists of functional deficiency of the anterior pituitary lobe, which appears during infancy or adolescence. The magnetic resonance findings in 10 patients with a history of primary hopopituitarism are presented. The findings include: reduced pituitary size in all cases: partially (8 cases) or totally (2 cases) empty sella; thin (4 cases), partially visible (3 cases) or absent (2 cases) pituitary stalk; absence of the posterior lobe in 9 cases: bright spot corresponding to an ectopic posterior lobe in 8 cases. These findings are similar to those already reported in pituitary dwarfism and may help under-genesis of the pathogenesis of the disease: which seems to he related to a pituitary stalk lesion.     

Value of petrosal sinus sampling: coexisting acromegaly,empty sella and meningioma

Simultaneous occurrence of an intracranial meningioma and a growth hormone (GH)-producing pituitary adenoma is exceedingly rare, as is coexistence of an empty sella and acromegaly. We report all these rare entities in the same patient. We evaluated the role of inferior petrosal sinus sampling for lateralisation of an adenoma in this patient.     

MR imaging of the pituitary stalk: size, shape, and enhancement pattern.

The size, shape, signal intensity, and enhancement pattern of the normal pituitary stalk were determined retrospectively by review of MR images of 58 patients. The pituitary stalk was measured at the level of the optic chiasm and at its insertion on the pituitary gland. The contour of the stalk was smoothly tapering, measuring 3.25 +/- 0.56 mm in transverse diameter at the optic chiasm and 1.91 +/- 0.40 mm at its pituitary insertion. The signal intensity of the pituitary stalk on unenhanced T1-weighted images was less than that of the neurohypophysis in all cases and less than that of the optic chiasm in 84% of the cases. After the administration of contrast material, enhancement of the pituitary stalk occurred in all cases. A central area of nonenhancement in an otherwise uniformly enhancing stalk was variably present, depending on the size of the infundibular recess. Our study defines the size, contour, and MR signal characteristics of the normal pituitary stalk. These criteria can be used to distinguish the normal from the abnormal stalk.     

MR of the hypothalamic-pituitary axis in Langerhans cell histiocytosis.

PURPOSE: To describe the MR findings in the hypothalamic pituitary area in children with Langerhans cell histiocytosis and to define those MR alterations especially associated with the risk of developing diabetes insipidus. METHODS: The hypothalamic-neurohypophyseal axis was studied by sagittal and coronal 1.5 T1-weighted MR imaging in 14 children with Langerhans cell histiocytosis (five with diabetes insipidus) and in 28 low-stature controls, ages 6-14 years. RESULTS: The pituitary stalk was thicker in seven/14 patients (three with diabetes insipidus) than in controls (P less than .05). Bright posterior pituitary signal was undetectable in children with diabetes insipidus and in one/9 without diabetes insipidus. CONCLUSIONS: Thickening of the hypothalamus and/or the pituitary stalk in the absence of the posterior pituitary bright signal is seen in children with Langerhans cell histiocytosis with overt diabetes insipidus. Those Langerhans cell histiocytosis patients without diabetes insipidus but showing thickened stalk with or without posterior pituitary bright signal could be at high risk to develop diabetes insipidus.     

中枢性尿崩症的MR影像诊断(附65例分析)

目的：分析中枢性尿崩症（ＣＤＩ）的ＭＲ表现，探讨ＭＲ在ＣＤＩ的影像诊断中的价值及限度。材料与方法：对１９９６－０６～１９９６－０７间所确诊的６５例ＣＤＩ患者的ＭＲ资料和临床资料进行了回顾性分析。结果：１、ＭＲ表现：鞍内／鞍上肿块１６例；垂体柄断裂或显示不清１４例；垂体柄增粗１０例；垂体柄结节５例；垂体后叶高信号消失５８例。２、引起ＣＤＩ的病因：头颅损伤６例；颅内肿瘤１７例；Ｌａｎｇｅｒｈａｎ＇ｓ组织细胞增生症２例；特发性ＣＤＩ１７例。有２３例继发性ＣＤＩ的病因未经病理证实。结论：低场强（０．３Ｔ）的ＭＲ机器能够清楚地显示下丘脑－垂体区的病变，对ＣＤＩ病因的诊断和治疗具有重要的价值，但对肿瘤及炎性病变的定性诊断有一定的限度，同时认为临床上划分的部分性ＣＤＩ和完全性ＣＤＩ的ＭＲ影像表现不存在差别。     

垂体柄阻断综合征的影像学诊断

目的分析垂体柄阻断综合征的CT及MRI表现,提高对其的认识及诊断水平。方法回顾性分析4例垂体柄阻断综合征患者的影像学及临床资料。结果4例患者中,2例CT及4例MRI垂体柄均未见显示,垂体窝内垂体后叶高信号均消失,4例均在第三脑室漏斗隐窝可见高信号小结节。结论MRI是确诊垂体柄阻断综合征最有效的影像学检查方法。     

A rare cause of hyperprolactinemia: persistent trigeminal artery with stalk-section effect

The primitive trigeminal, otic, hypoglossal, and proatlantal intersegmental arteries are fetal anastomoses between the carotid and vertebrobasilar systems. Persistent trigeminal artery (PTA) is the most frequent embryonic communication between the vertebrobasilar and carotid systems in adults. We report a case of PTA compressing the left side of the pituitary gland and stalk, in a patient with elevated blood prolactin level. Received: 28 February 2000 Revised: 7 June 2000 Accepted: 9 June 2000