lemon2008 发表于 2011-10-17 20:07:07


Young adult man with headache,年青患者头痛
Review the image below. Which choice best localizes the salient abnormality, if one is visible?
A Subdural space. 硬膜下间隙
B Sylvian fissure. 侧裂
C Tectal region. 顶盖区
D Frontal sinus. 额窦
E No visible abnormality on CT.下图无明显异常

lemon2008 发表于 2011-10-17 20:24:37

Findings (Brain): 脑CT表现:
CT Head: The third and fourth ventricles are midline and the lateral ventricles are not displaced. Hydrocephalus is not present. There is hyperdensity in the region of the pineal gland. Fragmented calcification in the pineal region is not present. Therefore, germinoma is favored in the differential diagnosis over pineoblastoma.

MRI Brain: 脑MRI表现
There is a midline enhancing pineal region mass which measures approximately 17mm in greatest anterior-posterior dimension (2nd and 3rd image above). There is leptomeningeal enhancement, particularly along the superior vermian cistern and within the sulci of the cerebellum bilaterally (4th image above). This is consistent with leptomeningeal carcinomatosis. There is no hydrocephalus.

lemon2008 发表于 2011-10-17 20:29:56

Findings (Spine): 影像表现(脊椎):

MRI C-Spine: There is diffuse nodular enhancement along the ventral and dorsal surface of the cervical cord consistent with diffuse leptomeningeal metastatic disease in this patient with a pineal region tumor. Similar abnormality is also present in the visualized upper thoracic spine. Notably, there is fairly thick enhancement dorsal to the upper thoracic cord.

MRI L-Spine: In the lumbar spine, normal cauda equina nerve roots are not well visualized. On the T1 sequence (2nd image above), CSF signal is slightly more hyperintense than normal. On the T2 sequence (3rd image above), CSF is more hypointense than normal. This suggests an abnormality in the thecal sac which is evident on post-contrast images. There is intense, confluent intradural enhancement (4th image above) along the entire cauda equina consistent with extensive drop metastases and additional leptomeningeal carcinomatosis.

Differential diagnosis:鉴别诊断:
Pineoblastoma 成松果体细胞瘤(松果体母细胞瘤)。
Germinoma. 生殖细胞瘤
Pineocytoma. 松果体瘤
Meningioma. 脑膜瘤
Pineal cyst.松果体囊肿

Pineoblastoma with drop metastases 松果体母细胞瘤下行转移
脑脊液转移瘤(下行转移, Drop Metastases):强化后多倍于脊髓信号

lemon2008 发表于 2011-10-17 20:55:23

Pineoblastomas are rare primary parenchymal tumors of the pineal gland that belong to the broader primitive neuroectodermal tumor (PNET) family. Conservative estimates of their frequency estimate their incidence to be 0.15 - 0.20% of all primary brain tumors. These highly malignant lesions are classified as WHO grade IV and are the most aggressive of the pineal parenchymal tumors. They occur most commonly in the first decade of life, although their incidence has been reported up to age 30. Treatment includes any combination of surgery, radiation, and chemotherapy. The estimated 5 year survival rate is 58%.
    松果体母细胞瘤松果体主要的实质性肿瘤,属于原始神经外胚层肿瘤(primitive neuroectodermal tumor,PNET)。保守估计其发生率占全部原发型脑肿瘤的0.15 - 0.20%。WHO将其定为IV级,为高度恶性肿瘤,为松果体实质侵袭性最强的肿瘤。大多发生于人的第一个10年,也有报道为30岁,主要治疗包括外科手术、放疗和化疗联合治疗。5年生存率为58%。临床症状主要有三个方面:(1)颅内压增高 ;(2)邻近脑受压征:视力障碍,听力障碍,小脑征(躯干性共济失调和眼球震颤),丘脑下部损害而引起的多饮多尿、嗜睡和向心性肥胖;(3)内分泌症状:性征发育停滞和不发育。(4)其他症状

Pineoblastomas can be large in size and are not uncommonly found to grow to over 3cm. This size often leads to compression of the Aqueduct of Sylvius and resultant hydrocephalus. The patient's presenting symptoms are often related to the presence of this mass-occupying lesion in the brain and are most commonly headache, nausea, vomiting, and papilledema. If the pineoblastoma is large enough to compress the dorsal midbrain, it can cause Parinaud's syndrome. Any young child who presents with these gaze palsies and symptoms of elevated intracranial pressure should be evaluated for pineoblastoma.

CT and MRI are the primary modalities for diagnosing and characterizing pineoblastoma. The mass can range from isodense to hyperdense on CT, but is frequently hyperdense. It may display peripheral calcifications that represent displaced native pineal gland calcium. This appearance of an "exploded" pineal gland is a classic one, but not present all the time. Pineoblastomas display isointense to hypointense signal on T1WI and variable intensity on T2WI, but characteristically enhance strongly on post-contrast images. Other diagnostic features of pineoblastomas include avid uptake of F-18 FDG on PET imaging and the lack of a distinctive pattern of serum tumor markers.
    CT 和MRI 是诊断松果体母细胞瘤的主要检查方法,CT上呈等密度或稍高密度灶,很少见到低密度。周边钙化见于原松果体钙化灶发生移位,典型表现为“爆裂”松果体,但并非所有病例都可见到。松果体母细胞瘤在MRI TIWI上表现等、低信号,T2WI信号多变,但增强后呈明显强化。 PET图像F-18 FDG 高摄取,无明显血清肿瘤标志物。

Pineoblastomas exhibit many radiologic findings that allow them to be distinguished from other possible neoplasms in their location. They generally tend to be poorly circumscribed lesions that invade local structures. Pineoblastomas can demonstrate peritumoral edema. Necrosis is frequent and hemorrhage is uncommon. Pineoblastoma has a strong tendency to seed the CSF. In fact, diffuse tumor invasion of the thecal sac resulting in a "sugarcoating" effect of carcinomatosis is not an uncommon finding.

The differential diagnosis of pineal gland masses includes germinomas (and other germ cell tumors), and pineocytomas.Meningiomas and metastases are other very rare possibilities. Germinomas account for 50% of all pineal region tumors. While pineoblastomas classically explode the gland with peripheral calcifications, germinomas are said to "engulf" the gland and keep its central calcification intact. Pineocytomas are better differentiated, more benign cousins of pineoblastomas. As their behavior would suggest, they often appear as a well-defined, homogenous mass with variable calcifications.

Key Points: 关键点:

1) In patients with suspected pinealoblastoma, the entire neuroaxis should be imaged to evaluate for drop metastases.
2) The main differential consideration in germinoma.
3) Pineoblastoma and germinoma are frequently hyperdense on CT.
4) "Gray" CSF and lack of visualization of the cauda equina nerve roots on lumbar spine MRI raises the concern for an abnormality in the thecal sac such as leptomeningeal carcinomatosis.
4) 在腰椎MRI上见到“灰色”脑脊液、看不到马尾神经根表明硬膜囊病变,比如软脑膜癌。

References: 参考文献:
1. Brant, Helms. Fundamentals of Diagnostic Radiology. Lippincott, Williams, and Wilkins; 2007. Pg 146-147.
2. Yousem, Grossman. The Requisites: Neuroradiology. Mosby Elsevier; 2010. Pg 94-98.
3. Statdx.com. Dx: Pineoblastoma.

KBG 发表于 2011-10-20 21:15:13


期待 发表于 2011-10-22 23:41:48

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