PET/CT imaging of conus medullaris metastasis from lung cancer

An intradural extramedullary metastasis is usually detected at an advanced stage of the disease or during workup for manifestations of spinal cord compression. Early diagnosis of such a lesion is rare and mostly fortuitous. The authors present a case of treated nonsmall cell lung carcinoma with an asymptomatic conus medullaris metastasis, which was demonstrated by PET/CT imaging during restaging evaluation.     

Intramedullary Spinal Cord Metastases: Visibility on PET and Correlation with MRI Features

BACKGROUND AND PURPOSE:Studies systematically evaluating the detection of intramedullary spinal cord metastasis with PET are lacking. Our purpose was to evaluate the visibility of intramedullary spinal cord metastasis on PET in a single institutional series and to correlate PET and MR imaging features.MATERIALS AND METHODS:Patients were included if pretreatment MR imaging identifying an intramedullary spinal cord metastasis and an [¹⁸F] FDG-PET examination near the time of MR imaging were available. PET examinations were retrospectively reviewed, with reviewers blinded and then unblinded to the PET report and MR imaging findings. PET intramedullary spinal cord metastasis features were compared with and correlated with previously analyzed MR imaging lesion characteristics. Original clinical PET reports were reviewed.RESULTS:The final study sample was 10 PET examinations in 10 patients with 13 intramedullary spinal cord metastases. In 7 (70%) patients, retrospective blinded review demonstrated convincing evidence of 10 (77%) intramedullary spinal cord metastases. Three MR imaging features correlated with intramedullary spinal cord metastases being visible on PET compared with those nonvisible, respectively: larger lesion enhancement size: mean size: 32.1 mm versus 6.0 mm (P = .038); larger longitudinal extent of T2 signal abnormality: mean 5.6 versus 1.0 segments (P = .0081); and larger ratio of extent of T2 signal abnormality to contrast enhancement: 3.8 versus 1.0 (P = .0069). Intramedullary spinal cord metastasis was confidently reported clinically in 2 (20%) patients, accounting for 5 (38%) intramedullary spinal cord metastases.CONCLUSIONS:Most intramedullary spinal cord metastases can be detected on PET when performed near the time of pretreatment MR imaging. However, intramedullary spinal cord metastases may not be clinically reported on PET. Larger lesions with more edema are more likely to be visible. The spinal cord should be specifically and carefully assessed on PET for evidence of intramedullary spinal cord metastases to provide timely diagnosis.

Intramedullary spinal cord metastases (ISCMs) are rare and devastating manifestations of metastatic neoplasm. They are present at autopsy in 0.9–2.1% of patients with cancer^1,2 and comprise 1–4% of spinal metastases.^1–3 Early detection is important because ISCMs indicate a poor prognosis, and treatment may slow neurologic deterioration.⁴ However, ISCMs can be asymptomatic, especially at early stages, and are historically difficult to detect with imaging.^3,5 MR imaging is the cornerstone of spinal cord imaging,⁶ but this technique is generally not indicated for screening of asymptomatic patients.[¹⁸F] FDG-PET is the primary imaging technique used for whole-body screening for metastases and therefore is a technique that ideally locates most sites of metastases, including intraspinal. However, there are only scattered case reports of visualization of ISCMs on PET.^7–12 No large series systematically evaluating the detection of ISCMs with PET have been reported. The purpose of the current study was to retrospectively evaluate the visibility of ISCMs on PET in a single institutional series of patients with ISCMs, and to correlate PET and MR imaging features.     

Leptomeningeal carcinomatosis and intramedullary spinal cord metastases from lung cancer: detection with FDG positron emission tomography

A 64-year-old man with a history of large-cell lung carcinoma and recent resection of a brain metastasis was examined because of a general decline in his ability to function. Whole-body positron emission tomography with fluorine-18 fluorodeoxyglucose (FDG PET) showed metastases along the spinal cord that were confirmed with MRI. Intramedullary spinal cord metastasis occurs rarely, and the prognosis is extremely poor. Whole-body FDG PET allows the entire spinal cord to be examined noninvasively compared with magnetic resonance imaging, computed tomography, and myelography.     

CT and MR imaging of laryngeal metastasis from renal cell carcinoma: A case report

Laryngeal metastasis is an extremely rare condition. To the best of our knowledge, there has been no previous report on a laryngeal metastasis from renal cell carcinoma, which describes on details of the CT and MR imaging findings. A male patient in his 80s. Laryngoscopy revealed reddish-colored masses in the right false vocal cord and in the subglottic larynx. CT and MR imaging of this case showed multiple hypervascularized lesions with a wash-out effect in the supra and subglottis of the larynx and in the right intervertebral foramen of the cervical spine. Angiography revealed a hypervascular tumor consistent with the subglottic lesion. The histopathology and immunohistochemistry findings were compatible with laryngeal metastasis from renal clear cell carcinoma. A history of postoperative renal clear cell carcinoma about 7 years ago was later confirmed, which was not stated at the time of the initial imaging evaluation. It is a possible differential diagnosis in cases of multiple hypervascular masses in the head and neck region with a history of renal carcinoma. In particular, if the contrast-enhancement pattern of the lesion on the dynamic CT is similar to that of renal cell carcinoma. It is also important to reconfirm the patient''s medical history, including postoperative status.     

18F-FDG PET/CT检测淋巴结转移性鳞癌原发灶的价值

目的 探讨18F-氟脱氧葡萄糖（FDG） PET/CT在淋巴结转移性鳞癌原发灶检测中的临床应用价值。 方法 选取2018年3月至2020年11月于广东省佛山市禅城区中心医院因发现淋巴结转移性鳞癌而原发灶不明行全身18F-FDG PET/CT检查的56例患者进行回顾性研究,其中男性44例、女性12例,年龄19~81岁,中位年龄51岁。所有患者的淋巴结转移性鳞癌均于18F-FDG PET/CT显像前经组织病理学检查确诊,原发灶经组织病理学检查或临床随访确诊。分析并计算18F-FDG PET/CT检测原发灶的检出率;原发灶与淋巴结转移部位、最大标准化摄取值（SUV_max）的关系。采用双变量相关分析法分析原发灶与淋巴结转移灶的SUV_max的相关性。 结果 56例患者中,18F-FDG PET/CT检测原发灶阳性44例（真阳性42例、假阳性2例）,检出率为75.0%;假阴性1例（鼻咽癌）;11例患者18F-FDG PET/CT未发现原发灶。双变量相关分析结果显示,原发灶与淋巴结转移灶的SUV_max在一定程度上具有一致性（r=0.320,P<0.05）。 结论 18F-FDG PET/CT显像对淋巴结转移性鳞癌的不明原发灶检测具有较好的临床应用价值,淋巴结转移灶与原发灶的18F-FDG代谢强度存在良好的相关性。     

Thyroid metastasis from primary renal cell cancer on FDG PET/CT

We report the PET/CT appearance of metastasis from primary renal cancer to the thyroid in a 52-year-old man with a history of right renal cell carcinoma, status postright nephrectomy, recently presented biopsied-proven metastatic lesion in his left thyroid lobe. Restaging PET/CT study demonstrates a 1.4 × 0.9 cm hypodense, moderately active lesion in the left thyroid lobe with a maximum SUV of 2.8. No other abnormal hypermetabolic lesion is seen in the right renal surgical bed or the remaining body. The patient has subsequently treated with Sutent (Sunitinib).     

Intramedullary spinal cord metastases, mainly of nonneurogenic origin

The clinical data and imaging studies of 12 patients with intramedullary metastases were reviewed retrospectively to see if these lesions had a typical radiographic appearance and to determine the sensitivity of the various radiologic examinations. The lesions were identified antemortem by either myelography, CT, MR, and/or intraoperative spinal sonography (IOSS). Final diagnosis was based on biopsy material from either the spinal cord lesion, another metastatic site, and/or the primary tumor. Ten patients had primary tumors located outside the central nervous system, while only two patients had primary brain tumors. Metrizamide myelography and CT demonstrated a definite intramedullary mass in nine of 11 patients. In five patients the mass was relatively small, well-defined, single, and resembled a primary spinal cord neoplasm. In the other four patients, longer and sometimes several segments of the cord were involved. These appeared irregular and nodular and were often associated with intradural lesions at separate sites. MR detected not only enlargement and abnormal signal in the cord but also clinically unsuspected brain lesions. IOSS localized lesions for biopsy and monitored tumor resection. These various imaging procedures showed that cord metastases were often more extensive than anticipated clinically. Spread of tumor into the spinal and intracranial subarachnoid space was common. Imaging of the entire spinal canal and brain, preferably with MR, is therefore recommended to aid in diagnosis, prognosis, and treatment.     

Pulmonary artery sarcoma detected on F-18 FDG PET/CT as origin of multiple spinal metastases

A 67-year-old man with back pain was diagnosed as having multiple spinal metastases on MRI. On CT scan, only a filling defect in the right pulmonary artery was observed and suspected as venous thromboembolism. On F-18 fluorodeoxyglucose (FDG) PET/CT, intense hypermetabolism was observed in the right pulmonary artery in addition to the metastatic spine lesions. Biopsy confirmed the lesion as a primary pulmonary artery sarcoma (PAS), and the spine lesions as metastases of PAS. Although PAS is rare and its bone metastasis presenting initial symptom is extremely rare, FDG PET/CT is an effective diagnostic modality for PAS, not only in discrimination from venous thromboembolism, but also in workup of metastatic origin.     

Spinal cord metastases from lung cancer: detection with F-18 FDG PET/CT

Preoperative F-18 FDG PET/CT study in this 57-year-old woman showed an FDG avid lesion in the left upper lung without evidence of lymphadenopathy or distant metastasis. She underwent a left upper lobectomy in June 2005 revealing moderately poorly differentiated adenocarcinoma (pT3N0M0) and subsequent chemotherapy completed December 2005. Nine months later, a left parietal lobe metastatic lesion was surgically resected. A true whole body FDG PET/CT study in November 2006 for restaging demonstrated new FDG avid spinal cord foci, which were highly suspicious for spinal cord metastases; these lesions were confirmed by MRI. Clinically, the patient recently developed back pain without evidence of neurologic deficits.     

Delayed CT myelography in spinal intramedullary metastasis

Solitary intramedullary metastasis to the spinal cord is rare and difficult to diagnose clinically. We report a case of lung carcinoma metastasizing to cervical spinal cord with an unusual feature of delayed metrizamide enhancement of the widened portion of the spinal cord. The role of CT in the diagnosis is well demonstrated in this case.     

Magnetic resonance imaging of intraspinal cystic lesions: a pictorial review

Magnetic resonance imaging is the imaging modality of choice for the evaluation of diseases of the spinal cord and its coverings primarily because of improved lesion detection and characterization. The differentiation of intramedullary pathologic conditions (arising within the spinal cord) from extramedullary lesions (lying either within the thecal sac (intradural) or outside it (extradural) is usually straightforward. Although many lesions may occur in more than one compartment or may extend to involve more than one compartment simultaneously, accurate positioning of a detected lesion within the spinal canal and the assessment of its signal characteristics may help differentiate many of the more commonly encountered lesions and aid preoperative diagnosis. This pictorial review discusses the imaging findings and distinguishing features of a variety of intramedullary and extramedullary intraspinal cystic lesions with the use of magnetic resonance imaging. The imaging appearances are correlated with histologic findings where available.     

Parotid Gland Metastasis From Squamous Cell Carcinoma of Esophagus Detected by FDG PET/CT

ABSTRACT: A 55-year-old man was diagnosed with squamous cell carcinoma in the middle thoracic esophagus. The FDG PET/CT revealed an incidental strong FDG-avid finding (SUVmax, 11) in the right parotid gland, which was subsequently confirmed as metastasis from the squamous cell carcinoma of esophagus via surgery. The current case adds another differential diagnosis of parotid FDG-avid lesion to the existing literature.     

Detection of Thyroid Metastasis of Renal Transitional Cell Carcinoma Using FDG PET/CT

A 69-year-old man who was diagnosed with renal transitional cell carcinoma (TCC) underwent F-18 fluorodeoxyglucose (FDG) positron emission tomography with computed tomography (PET/CT) for detecting recurrence after chemotherapy. FDG PET/CT revealed multiple new hypermetabolic lesions in many places, including the right thyroid gland. Biopsy of the thyroid lesion was performed, and a diagnosis of metastatic TCC was made. We could detect thyroid metastasis of renal TCC by FDG PET/CT.     

Spinal cord compression caused by dual pathology: a close shave with Ockham's razor

A case of spinal cord compression in an oncology patient is presented. The compression was caused by minimal expansion of a vertebral body involved by a metastatic deposit impinging on a previously asymptomatic lipomatous spinal cord tumour. Nuclear magnetic resonance imaging clearly demonstrated both the vertebral metastasis and the intramedullary and extramedullary components of the lipomatous tumour in a single noninvasive investigation.     

Multiple spinal intramedullary cavernous angiomas with bleeding episode mimicking an intramedullary tumor

Intramedullary cavernous angioma is a rare vascular malformation compared to cerebral cavernous malformation. The incidence of cavernous angioma is about 3 – 5% of all central nervous system lesions, 5 – 12% of all spinal vascular lesions, and 1% of all intramedullary lesions in pediatric patients. Although intramedullary cavernous angioma has the same histological picture as cerebral cavernous angioma, the natural history, and surgical approach are different from cerebral cavernous angioma. Due to its location in the eloquent area of the spinal medulla, a slight change in the size of the lesion can affect the neurological function of the patient. We describe a case of an intramedullary cavernous angioma with hemosiderin post bleeding, located in the cervical cord which was initially misdiagnosed as hemorrhagic ependymoma. On whole spine MR imaging we also found an intramedullary cavernous angioma in the lower thoracal cord at the T12 level with mild hemorrhage. Abdominal MRI showed cavernous angiomas in both kidneys. The patient underwent surgical treatment with removal of the lesion in the cervical cord and T12 level, with histopathologic findings consistent with cavernous angioma. No malignancy was detected. Post-surgery, the symptoms gradually improved. Symptomatic intramedullary cavernous angioma tends to bleed repeatedly and being unstable. Early diagnosis and surgical treatment can prevent rebleeding and more severe symptoms.     

A case of renal pelvic tumor visualized by<Superscript>18</Superscript>F-FDG-PET imaging

18F fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging is a useful modality in detecting various tumors, including renal cell carcinoma. We evaluated a patient with renal pelvic tumor (transitional cell carcinoma) with multiple metastases using 18F-FDG PET imaging and detected abnormal increased uptake of a right renal pelvic tumor extending to the renal cortex with liver metastasis and paraaortic lymph node metastases. These results suggest that 18F-FDG PET imaging may be useful in detecting primary and metastatic lesions of renal pelvic tumor (transitional cell carcinoma).     

Fluorine-18-fluorodeoxyglucose PET/CT rare finding of a unique multiorgan involvement of Wegener's granulomatosis

Wegener's granulomatosis (WG) is an uncommon autoimmune disorder, which mainly involves the blood vessels, kidneys and respiratory tract. We report an interesting case of WG with unusual multiorgan involvement in a young male who presented with a short history of right-sided otalgia, nasal obstruction and a right parotid mass. His initial CT and MRI scans showed a large parotid mass with features suggestive of malignancy with bilateral cavitating pulmonary nodules suggesting metastatic disease. The imaging-based differential diagnosis was squamous cell carcinoma or adenoid cystic carcinoma. The microscopic findings on ultrasound-guided biopsy of the parotid mass were, surprisingly, those of acute necrotising granulomatous inflammation with some features suggestive of a vasculitic process. A multidisciplinary team discussion and further investigation resulted in the additional findings of haematuria, raised erythrocyte sedimentation rate and positive serum cytoplasmic anti-neutrophil cytoplasmic antibody test, which led to the diagnosis of WG. Subsequently, the patient developed acute urinary retention owing to gross prostatic enlargement related to further disease involvement, which was confirmed with a positive biopsy. Fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT scan showed disease distribution at the right maxillary sinus/nasal cavity, right parotid, mediastinum, lungs and prostate. To our knowledge, this is the first reported 18F-FDG PET/CT case with multiorgan involvement in a single WG patient. The patient has improved both clinically and on imaging after appropriate treatment with immunosuppressive therapy and steroids. Although 18F-FDG PET/CT imaging did not actually alter the management of this patient, it can help to establish the disease distribution and guide the biopsy.     

Unusual Horner’s Syndrome in Recurrent Breast Cancer: Evaluation Using <Superscript>18</Superscript>F-FDG PET/CT

¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a widely used imaging modality in the initial diagnosis of cancer, treatment response evaluation and detection of recurrence. Herein, we present the case of a 39-year-old female who presented right ptosis on the follow-up of breast cancer after surgery. Clinicians suspected Horner’s syndrome, and the patient underwent FDG PET/CT for the evaluation of recurrence that could cause Horner’s syndrome. FDG PET/CT demonstrated a focal hypermetabolic lesion in the right cervicothoracic junction area, corresponding to the preganglionic cervical sympathetic trunk. A subsequent needle biopsy was done, and the lesion was confirmed as metastatic ductal carcinoma. In this case, we could detect the exact location of the recurring lesion that caused Horner’s syndrome using FDG PET/CT.     

Imaging of tumors of the spine and spinal cord

Imaging of the spine and spinal cord has traditionally been accomplished with plain radiography, myelography, and CT. Recently, MR imaging has become the technique of choice in the assessment of lesions of the spine and spinal cord. MR imaging provides accurate localization of intramedullary, intradural extramedullary, and extradural tumors. Ependymomas and low-grade astrocytomas are the most common intramedullary tumors. MR imaging findings are distinguishable by the delineation and size of the lesion, and the signal intensity on T2-weighted images. Other less common tumors include malignant astrocytomas, hemangioblastomas, and intramedullary metastasis. Numerous foci of high-velocity signal loss are seen in the hemangioblastomas. Metastasis, meningiomas, and schwannomas are the most common intradural extramedullary tumors. Meningiomas are characterized by dural enhancement on postcontrast T1-weighted images. Schwannomas and neurofibromas often erode bony structures and appear to be dumbbell-shaped. Epidural metastasis accounts for the majority of extradural tumors. Primary malignant extradural tumors include lymphomas, chordomas, and so on. The most common primary benign extradural tumor is hemangioma, which often appears to be hyperintense on both T1-weighted and T2-weighted images. Intramedullary non-neoplastic lesions include demyelinating, vascular, and infectious diseases. Diffuse, peripheral, or speckled contrast enhancement, and lack of contrast enhancement may suggest non-neoplastic lesions.     

椎管内血管性病变的MRI诊断

目的 总结不同类型椎管内血管性病变的影像特点,以提高对该类疾病的诊断水平. 资料与方法 对33例经手术病理或DSA证实的椎管内血管性病变的影像及临床资料进行回顾性分析,其中海绵状血管瘤11例(髓内8例,髓外硬脊膜外3例),血管母细胞瘤4例(单发2例,多发2例),动静脉病变18例(动静脉瘘12 例,动静脉畸形6例).所有病例均行MR平扫和增强扫描. 结果 椎管内血管性病变好发年龄在40岁左右,临床多表现为渐进性的神经系统受损症状.海绵状血管瘤髓内较髓外相对多见,髓内病变颈段好发,病变多局限,病灶周围T2低信号环较具特征性,强化多不明显;硬脊膜外海绵状血管瘤少见,多发生在胸段,常为边界清楚梭型肿物,均匀明显强化.血管母细胞瘤较少见,可单发亦可多发,多发生在颈、胸段,当伴有较大范围脊髓空洞或囊变,并有明显强化结节时,诊断不难;动静脉病变最多见, MRI多能发现蜿蜒血管流空信号,较易诊断,但具体分型有赖于DSA或手术. 结论 椎管内不同类型的血管性病变具有相对特异的影像表现,MRI可较好地显示病变,并能准确定位,同时可以显示脊髓变性的程度和范围,有利于病变的诊治及判断预后.