Neurolinfomatosis de los nervios ciático y mediano como presentación inicial del linfoma de linfocitos B

Neurolymphomatosis (NL) is the infiltration of cranial nerves or nerves and roots from the peripheral nervous system by lymphoma, usually by B-cell non-Hodgkin's lymphoma. It is uncommon as initial presentation of the disease and can lead to extremely heterogeneous clinical manifestations. We report the case of a 72-year old male who presented with numbness of the right hand, progressive weakness in both lower limbs and weight loss. 18F-FDG PET/CT showed bilateral hypermetabolic adrenal masses, gastric ulcer, small hypermetabolic adenopathies, multiple focal bone marrow uptake and intense uptake in both sciatic nerves and right median nerve. A node and gastric biopsy confirmed diffuse large-B-cell lymphoma, activated B cell type, with posterior resolution of peripheral nerves uptake after beginning chemotherapy.     

原发性肺弥漫大B细胞淋巴瘤18F-FDG PET/CT显像一例

笔者报道了一例原发性肺弥漫大B细胞淋巴瘤的18F-FDG PET/CT显像病例,从临床症状、实验室检查、18F-FDG PET/CT影像学等方面分析该病特点,并通过文献回顾了原发性肺弥漫大B细胞淋巴瘤鉴别诊断要点。研究结果显示,本例原发性肺弥漫大B细胞淋巴瘤18F-FDG PET/CT影像学表现为巨大软组织团块影、边缘光滑、内见多发点状钙化灶,18F-FDG代谢团块状增高,SUV_max为26.2。18F-FDG PET/CT显像能够为原发性肺弥漫大B细胞淋巴瘤的诊断提供参考依据。     

继发性骨淋巴瘤的18F-FDG PET/CT影像学表现

目的 探讨继发性骨淋巴瘤在18F-FDG PET/CT显像中的影像学特点。 方法 对2012年4月至2015年6月行全身18F-FDG PET/CT显像的46例继发性骨淋巴瘤患者的PET/CT影像学表现进行回顾性分析。并将骨髓穿刺结果分为阳性和阴性两组,对两组显像相应穿刺部位（髂棘）SUV进行独立样本t检验,同时绘制穿刺部位SUV诊断继发性骨淋巴瘤的受试者工作特征曲线（ROC）。 结果 46例继发性骨淋巴瘤患者中,霍奇金淋巴瘤6例、非霍奇金淋巴瘤40例;单发10例,多发18例,全身弥漫分布18例。46例患者骨质异常表现多样,其中,骨髓浸润型31例（67.40%）、混合型10例（21.74%）、硬化型3例（6.52%）、溶骨型2例（4.34%）。46例患者中肱骨或股骨受累32例（69.57%）,均为骨髓浸润型表现。骨髓穿刺阳性组及阴性组SUV独立样本t检验结果显示t=4.036,P < 0.001,提示两组差异有统计学意义。穿刺部位SUV诊断继发性骨淋巴瘤的ROC曲线结果显示SUV诊断界值为2.35,其诊断继发性骨淋巴瘤的特异度和灵敏度分别为83.3%和80.0%。 结论 继发性骨淋巴瘤的18F-FDG PET/CT影像学表现存在一定的特征性,在该病的诊断与鉴别诊断中具有重要的临床价值,且对骨髓穿刺部位的选择具有指导意义。     

全身MRI与PET/CT在淋巴瘤骨髓浸润诊断及预后中的作用

淋巴瘤是一种血液系统恶性肿瘤。淋巴瘤骨髓浸润(BMI)使疾病分期上升至IV期, 是疾病进展、预后较差的标志。常规部位的骨髓活检(BMB)具有创伤性, 且检出率低。PET/CT与全身MRI的出现, 丰富了BMI的检测手段。PET/CT与全身MRI对于淋巴瘤, 尤其是侵袭性淋巴瘤BMI均具有较高的检出率, 二者孰高孰低, 尚未定论。对于红骨髓、良性骨髓病变(炎症等)、淋巴瘤BMI病灶以及肿瘤治疗后骨髓的变化与骨髓残留或复发病灶, 全身MRI很难区分, 而PET/CT却可以很好地鉴别这些病灶。但是, PET/CT存在电离辐射; 对于惰性淋巴瘤的BMI, 超出PET/CT分辨率的病灶, 可能出现假阴性; 某些情况会限制PET/CT的使用, 包括18F-FDG生理性摄取量可能发生改变的正常组织、18F-FDG摄取相关性炎症、高血糖或高胰岛素血症导致的18F-FDG分布的改变、肿瘤患者治疗后出现的骨髓活化等。然而, 这些情况可以使用全身MRI。因此, 全身MRI和PET/CT相辅相成, 优势互补, 但二者均不能代替BMB。对于常规BMB阴性, 但影像学提示阳性的患者, 在影像学引导下进行BMB, 可以提高BMI的检出率。另外, 全身MRI阳性的淋巴瘤BMI患者与全身MRI阴性的淋巴瘤BMI患者相比, 前者预后可能较差。     

Usefulness of 18F-FDG PET/CT for the Evaluation of Bone Marrow Involvement in Patients with High-Grade Non-Hodgkin’s Lymphoma

Purpose

To assess the usefulness of ¹⁸F-fluorodeoxyglucose PET/CT in the detection of bone marrow (BM) involvement of high-grade non-Hodgkin’s lymphoma (NHL).

Methods

One hundred twenty patients with newly diagnosed diffuse large B-cell lymphoma or peripheral T-cell lymphoma between January 2007 and June 2011, who received BM trephine biopsy and ¹⁸F-FDG PET/CT before chemotherapy, were included in this retrospective study. We reviewed their ¹⁸F-FDG PET/CT images and bone marrow biopsy (BMB) results. After reviewing the images, we reviewed the medical records and radiological findings of interesting patients.

Results

There were 23 ¹⁸F-FDG PET/CT scans in which the marrow was considered to be abnormal (either positive or equivocal), and 97 ¹⁸F-FDG PET/CT scans were regarded as having negative FDG uptake. Of 120 patients, 100 (83.3 %) had a concordant result of BM interpretation between ¹⁸F-FDG PET/CT and BMB, and the remaining 20 patients had discordant results. Among 23 patients with either positive or equivocal ¹⁸F-FDG PET/CT scans, 1 of 12 patients with ‘positive’ ¹⁸F-FDG PET/CT had a lymphomatous involvement on BMB. In contrast, 10 of 11 patients with ‘equivocal’ BM hypermetabolism were reported as having positive involvement by BMB. Patients with abnormal ¹⁸F-FDG PET/CT had significantly higher mSUV_highest than those with normal FDG-PET/CT.

Conclusions

¹⁸F-FDG PET/CT and BMB are complementary techniques in assessing the presence of BM involvement in patients with high-grade NHL. The increasing availability of ¹⁸F-FDG PET/CT will raise the need for additional biopsy for FDG-avid lesions, especially in patients with negative standard BMBs. ¹⁸F-FDG PET/CT can be useful as a decision-making tool for determining whether to perform a standard BMB or targeted biopsy to the FDG-avid lesion as an initial staging procedure. A direct bone biopsy for FDGpositive bone lesions should be included in staging guidelines in future. In ¹⁸F-FDG PET/CT-negative cases, BMB is still a powerful procedure, but BMB alone is insufficient for full evaluation of BM.     

Splenic and bone marrow increased 18F-FDG uptake in a PET scan performed following treatment with G-CSF

We present the case of an 11 year-old Caucasian girl who presented chest pain of 12 weeks evolution, with no other symptoms and a negative physical examination. Lactate dehydrogenase levels were increased to 797 U/l, whereas beta-2-microglobulin (BM2) levels were normal. The thoracic CT showed a bulky mediastinal mass that occupied the pretracheal, paratracheal and right prevascular regions. The gallium scintigraphy showed high uptake in the mediastinic region; the bone scintigraphy was negative. Biopsy of the mediastinal mass revealed the presence of diffuse large B-cell non-Hodgkin's lymphoma. Treatment included 4 cycles of chemotherapy followed by 7 days of subcutaneous granulocyte colony-stimulating factor (G-CSF, Lenogastrim) at a dose of 5 mg/Kg/day. Following treatment, a CT scan was performed to evaluate response, finding a calcification of the mass without significant reduction of the overall size. Because CT was inconclusive in the assessment of response to therapy, a 18F-FDG PET scan was performed. The 18F-FDG PET scan did not show any pathological uptake in the mediastinum but revealed a splenic and bone marrow diffusely increased 18F-FDG uptake. The differential diagnosis included a secondary effect induced by G-CSF therapy as one of the main possibilities, but other possibilities such as a malignant infiltration by lymphoma could not be discarded. Therefore, a second 18F-FDG PET scan was performed 3 months later. This study showed no pathological findings, with a normal 18F-FDG uptake in the spleen and bone marrow. Thus, the benign and reactive nature of the splenic and bone marrow 18F-FDG increased uptake found in the previous study was confirmed. We consider that the stimulating effect that G-CSF therapy has on the spleen and bone marrow must be taken into account when performing a 18F-FDG PET scan, as it can be an important source of false-positive results.     

多发性骨髓瘤的18F-FDGPET/CT诊断

目的:多发性骨髓瘤是一种浆细胞恶性增殖性疾病,大约有80％的患者存在骨骼侵犯.本文探讨多发性骨髓瘤的18F-fluorodexoxyglucose(18F-FDG)PET/CT表现特点,提高对多发性骨髓瘤的认识.方法:26例按2001年WHO诊断标准确诊为多发性骨髓瘤的患者,均在治疗前行18F-FDG PET/CT显像.所有患者均依赖骨髓穿刺或活检取得明确病理学诊断.结果:26名患者均出现不同程度的骨质疏松.25例患者出现多发性骨质破坏,占总数的96.2％;其中11例患者出现颅骨破坏,占42.3％;25例出现脊柱骨质破坏,占96.2％;15例出现胸骨骨质破坏,占57.7％;21例出现肋骨骨质破坏,占80.8％;21例出现骨盆骨质破坏,占80.8％.部分骨破坏病灶呈18F-FDG高代谢灶.结论:多发性骨髓瘤的18F-FDG PET/CT表现具有一定特征,结合临床、影像、实验室和病理学检查能提高本病的诊断率.     

^18F-FDG PET/CT在POEMS综合征诊断中的应用

目的 总结多发性周围神经病、脏器肿大、内分泌病变、M蛋白和皮肤病变（POEMS）综合征的18F-FDG PET/CT表现,探讨^18F-FDG PET/CT在该病中的应用价值.方法 2008年10月至2013年2月间经临床证实的11例POEMS综合征患者[男7例,女4例,年龄49～73（58.5±8.4）岁],确诊前均行^18F-FDG PET/CT显像.总结病例的PET/CT图像特征,观察病灶^18F-FDG摄取情况.结果 11例患者均存在多发硬化性骨病变（141个）：顶骨5个,肩胛骨8个,锁骨4个,肋骨16个,椎体64个,髂骨29个,坐骨6个,耻骨8个,肱骨1个;其中58个PET显像阳性,SUVmax为4.3±1.6.肝脏肿大者1例,脾脏肿大者3例,同时存在肝、脾肿大者2例;其中有3例肿大脾脏FDG摄取增高,SUVmax为3.2～4.1.5例患者多发淋巴结肿大,均可见FDG摄取增高,SUVmax为2.6～4.9.胸腔积液者1例,腹腔积液者3例,盆腔积液者3例,三者并存2例,且这2例合并存在皮下水肿,均未见异常^18F-FDG摄取.结论 ^18F-FDG PET/CT可以同时发现POEMS综合征的骨损害、脏器肿大以及血管外水容量过负荷等多系统病变,其表现具有一定的特征性,能为临床进一步诊治提供依据.     

Computed tomography enterography and 18F-FDG PET/CT features of primary signet ring cell carcinoma of the small bowel in a patient with Crohn's disease

We report a case of a primary signet ring cell carcinoma (PSRCC) of the small bowel in a patient with long-standing Crohn's disease, describing computed tomography (CT)-enterography (CTE) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT features of this rare tumor. CTE demonstrated submucosal thickening of a long ileal segment with preserved mural stratification. PET/CT examination showed increased 18F-FDG uptake in the affected ileal loop, hypermetabolic abdominal and mediastinal lymphadenopathies, and multiple hypermetabolic bone lesions. Iliac crest osteo-medullary biopsy revealed bone marrow infiltration by “signet ring” cells with intestinal differentiation. Double-balloon enteroscopy was used to obtain biopsies that confirmed the ileal origin of the PSRCC.     

Multicentric Primary Angiosarcoma of Bone Mimicking Metastasis on 18F-FDG PET/CT in a Patient with a History of Sigmoid Colon Cancer: a Case Report

Primary angiosarcoma of the bone (PAB) is a rare and fatal high-grade malignant vascular bone tumor. We report a rare case of multicentric PAB mimicking bone metastasis in a 59-year-old female patient with a history of sigmoid colon cancer. This patient complained of lower back and pelvic pain and presented with multiple osteolytic bone lesions on plain radiography and pelvic computed tomography. First, bone metastasis of sigmoid colon cancer was suspected. However, on the ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) scan, the patient presented unusual multiple hypermetabolic osteolytic bone lesions involving contiguous bones of the lower half of the body. After bone biopsy, these lesions were confirmed to be multicentric PAB. To the best of our knowledge, this is the first case report of an ¹⁸F-FDG PET/CT scan in a patient with multicentric primary bone angiosarcoma.     

Usefulness of F-18 FDG PET/CT in the follow-up of POEMS syndrome after autologous peripheral blood stem cell transplantation

We report a case of a patient with relapse of POEMS syndrome (peripheral neuropathy, organomegaly, endocrinopathy, monoclonal plasma proliferative disorder, skin changes) that occurred 6 years after an autologous peripheral blood stem cell transplantation. F-18 FDG PET/CT showed several hypermetabolic as well as nonhypermetabolic bone lesions. Based on these findings, the patient was referred for radiotherapy to the hypermetabolic bone lesions. After autologous peripheral blood stem cell transplantation, F-18 FDG PET/CT may play a pivotal role in detecting new bone lesions in patients with POEMS syndrome, which may be treated by a focalized radiotherapy and/or systemic therapy.     

Unsuspected Active Sarcoidosis Diagnosed by 18F-FDG PET/CT During the Search for a Primary Tumour in a Patient with Bone Lesions

Sarcoidosis is a systemic chronic inflammatory disease of unknown aetiology, characterised by granulomatous lesions with heterogeneous clinical manifestations affecting multiple organs and tissues. Although the respiratory system is most commonly affected, the disease may also present with bone lesions. We report the case of a 31-year-old woman who presented with low back pain and no history of cancer and who was found to have suspicious lesions involving the entire spine on magnetic resonance imaging (MRI). The patient underwent 18F-fluorodeoxyglucose (FDG) PET/CT to search for a primary tumour and for staging purposes. 18F-FDG PET/CT revealed a pattern of hypermetabolic activity in widespread skeletal lesions and in a single left cervical lymph node. The primary tumour was not found, thus suggesting a haematologic disorder. Subsequent biopsies of a cervical lymph node and of bone tissue from L4 revealed active sarcoidosis with no evidence of cancer. This underlines the importance of considering all alternatives when hypermetabolic lesions are found on 18F-FDG PET/CT. Furthermore, 18F-FDG PET can be very useful to indicate accessible sites for guiding fine-needle aspiration cytology (FNAC).     

18F-FDG PET/CT Diagnosis of Vagus Nerve Neurolymphomatosis

ABSTRACT: A 62-year-old woman was in remission from previously treated stage IV diffuse large B-cell lymphoma with cranial involvement. She presented with new-onset hoarseness of voice and choking; MRI of the brain showed disease recurrence in the left cavernous sinus. She was subsequently referred for F-FDG PET/CT with contrast for further evaluation of lymphomatous recurrence. F-FDG PET/CT not only revealed hypermetabolic activity in the left cavernous sinus correlating to the MRI findings but also showed an interesting manifestation explaining the patient's hoarseness of voice, being neurolymphomatosis along the left vagus nerve.     

Usefulness of 18F-fluoride PET/CT in Breast Cancer Patients with Osteosclerotic Bone Metastases

Purpose

Bone metastasis is an important factor for the treatment and prognosis of breast cancer patients. Whole-body bone scintigraphy (WBBS) can evaluate skeletal metastases, and ¹⁸F-FDG PET/CT seems to exhibit high specificity and accuracy in detecting bone metastases. However, there is a limitation of ¹⁸F-FDG PET in assessing sclerotic bone metastases because some lesions may be undetectable. Recent studies showed that ¹⁸F-fluoride PET/CT is more sensitive than WBBS in detecting bone metastases. This study aims to evaluate the usefulness of ¹⁸F-fluoride PET/CT by comparing it with WBBS and ¹⁸F-FDG PET/CT in breast cancer patients with osteosclerotic skeletal metastases.

Materials and Methods

Nine breast cancer patients with suspected bone metastases (9 females; mean age ± SD, 55.6 ± 10.0 years) underwent ^99mTc-MDP WBBS, ¹⁸F-FDG PET/CT and ¹⁸F-fluoride PET/CT. Lesion-based analysis of five regions of the skeletons (skull, vertebral column, thoracic cage, pelvic bones and long bones of extremities) and patient-based analysis were performed.

Results

¹⁸F-fluoride PET/CT, ¹⁸F-FDG PET/CT and WBBS detected 49, 20 and 25 true metastases, respectively. Sensitivity, specificity, positive predictive value and negative predictive value of ¹⁸F-fluoride PET/CT were 94.2 %, 46.3 %, 57.7 % and 91.2 %, respectively. Most true metastatic lesions on ¹⁸F-fluoride PET/CT had osteosclerotic change (45/49, 91.8 %), and only four lesions showed osteolytic change. Most lesions on ¹⁸F-FDG PET/CT also demonstrated osteosclerotic change (17/20, 85.0 %) with three osteolytic lesions. All true metastatic lesions detected on WBBS and ¹⁸F-FDG PET/CT were identified on ¹⁸F-fluoride PET/CT.

Conclusion

¹⁸F-fluoride PET/CT is superior to WBBS or ¹⁸F-FDG PET/CT in detecting osteosclerotic metastatic lesions. ¹⁸F-fluoride PET/CT might be useful in evaluating osteosclerotic metastases in breast cancer patients.     

骨上皮样血管内皮瘤的CT、MRI及18 F-FDG PET/CT表现(附2例报道)

目的探讨骨上皮样血管内皮瘤(EHE)的CT、MRI及18 F-FDG PET/CT表现,以提高对该病的影像学认识。方法回顾性分析2例经病理证实的骨上皮样血管内皮瘤患者的CT、MRI及18 F-FDG PET/CT检查图像资料,总结其影像特点。结果2例骨EHE中,1例为全身多发骨骼病变,1例仅为胸11椎体病变。CT表现病灶为边缘清晰,轻度硬化并呈分叶状改变的膨胀性溶骨性骨质破坏,病灶内见散在斑点状高密度影,周边软组织及椎间盘未见明显受累。MRI病灶呈稍长T 1、长T 2信号,其内可见散在斑点状低信号影,增强扫描病灶呈明显不均匀强化。病灶外周可见增强无强化的低信号环。18 F-FDG PET/CT主要表现为病灶部位的溶骨性骨质破坏伴SUV摄取值的升高。结论CT、MRI及18 F-FDG PET/CT检查能帮助评估骨上皮样血管内皮瘤的病灶性质及范围,协助下一步诊疗方案的确定。     

Comparison of diagnostic ability between 99mTc-MDP bone scan and 18F-FDG PET/CT for bone metastasis in patients with small cell lung cancer

Objective

The aim of this study was to compare the diagnostic ability of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) with that of ^99mTc-methylene diphosphonate (^99mTc-MDP) bone scan for bone metastasis in staging patients with small cell lung cancer (SCLC).

Methods

Ninety-five patients with SCLC who underwent both ¹⁸F-FDG PET/CT and ^99mTc-MDP bone scan for initial staging work-up were retrospectively enrolled. All ¹⁸F-FDG PET/CT and bone scan images were visually assessed. Bone metastasis was confirmed by histopathological results and all available clinical information.

Results

Of 95 patients with SCLC, metastatic bone lesions were found in 30 patients, and 84 metastatic lesions were evaluated on a lesion-basis analysis. The sensitivity of ¹⁸F-FDG PET/CT was 100?% on a per-patient basis and 87?% on a per-lesion basis, and there was no false-positive lesion on PET/CT images. In contrast, the sensitivity of the bone scan was 37?% on a per-patient basis and 29?% on a per-lesion basis. The bone scan showed 11 false-positive lesions. The bone scan detected two metastatic lesions that were not detected by PET/CT, which were outside the region scanned by PET/CT. On follow-up bone scan, 21 lesions that were not detected by the initial bone scan but were detected by PET/CT were newly detected.

Conclusions

In patients with SCLC, ¹⁸F-FDG PET/CT showed higher detection rate of bone metastasis than ^99mTc-MDP bone scan. Thus, ¹⁸F-FDG PET/CT can replace bone scan in staging patients with SCLC.     

Role of 18F-FDG PET/CT in the assessment of bone involvement in newly diagnosed multiple myeloma: preliminary results

Purpose Multiple myeloma (MM) is a malignant B cell and plasma cell disorder which involves the skeleton in more than 80% of patients at diagnosis. The aim of this study was to compare whole-body X-ray (WBXR), MRI and ¹⁸F-FDG PET/CT in patients with MM. Methods The study population comprised 28 newly diagnosed MM patients. Findings of ¹⁸F-FDG PET/CT were compared with those of WBXR and MRI with regard to the number and site of lesions detected. Results Comparing ¹⁸F-FDG PET/CT and WBXR, it was found that in 16/28 pts (57%) ¹⁸F-FDG PET/CT detected more lesions, all of which were located in the skeleton. Nine of these 16 patients had a completely negative WBXR survey. In 12/28 pts (43%) the two methods yielded equivalent findings. Comparing ¹⁸F-FDG PET/CT and MRI, it was found that in 7/28 pts (25%), ¹⁸F-FDG PET/CT detected more lytic bone lesions, all of which were located outside the field of view of MRI (bone lesions in six cases and a soft tissue lesion in one). In 14/28 pts (50%), ¹⁸F-FDG PET/CT and MRI detected the same number of lesions in the spine and pelvis, while in 7/28 pts (25%) MRI detected an infiltrative pattern in the spine whereas ¹⁸F-FDG PET/CT was negative. Conclusion ¹⁸F-FDG PET/CT appears to be more sensitive than WBXR for the detection of small lytic bone lesions, whereas it has the same sensitivity as MRI in detecting bone disease of the spine and pelvis. On the other hand, MRI may be superior to ¹⁸F-FDG PET/CT in diagnosing an infiltrative pattern in the spine. Therefore, careful evaluation of MM bone disease at diagnosis should include both MRI of the spine and ¹⁸F-FDG PET/CT.     

血管免疫母细胞T细胞淋巴瘤^18MF-FDGPET/CT的影像表现及其在临床分期中的价值

目的分析血管免疫母细胞T细胞淋巴瘤（angioimmunoblasticT-celllymphoma,AITL）^18F-FDGPET/CT的影像学表现及分布规律,探讨其在临床分期中的价值。方法回顾性分析22例AITL患者的^18F-FDGPET/CT显像结果,评价其在临床分期中的价值。结果（1）AITL结内侵犯的^18F-FDGPET/CT影像学表现：①全身弥漫性分布：左右对称性分布9例（40．9％）,左右不对称性分布2例（9．1％）;②多部位散在分布：与淋巴链走行有关4例（18．2％）,与淋巴链走行无关5例（22．7％）;③单部位局限性分布2例（9．1％）;（2）AITL结外侵犯的^18F-FDGPET／CT影像学表现：鼻咽部侵犯最常见有10例,其余依次为口咽8例,脾脏8例,骨骼及骨髓5例,胃肠道4例,肺、胸膜及皮肤各2例,乳腺及颅内侵犯各1例;（3）在AITL分期中的价值：PET/CT显像改变了4例（18．2％,4/22）患者的分期,均为分期上调。结论血管免疫母细胞T细胞淋巴瘤呈”F-FDG高摄取;其在病灶检测及分期方面,^18F-FDGPET/CT显像有优势。     

Detection of Richter's transformation of chronic lymphocytic leukemia by PET/CT.

Our objective was to evaluate the accuracy of PET/CT for the diagnosis of Richter's transformation of chronic lymphocytic leukemia (CLL) to diffuse large cell lymphoma. METHODS: A retrospective study was performed of 37 patients with CLL who underwent 18F-FDG PET/CT at our institution between March 2003 and July 2005. All PET/CT scans were reviewed in consensus by 2 diagnostic radiologists. Sites of abnormal 18F-FDG uptake with a maximum standardized uptake value (SUVmax) of greater than 5 were considered highly suggestive of Richter's transformation. The PET/CT findings were correlated with histologic findings from bone marrow or lymph node biopsy performed within 6 wk of PET/CT and with clinical follow-up. RESULTS: The 37 patients (26 men and 11 women; mean age, 61 y, range, 40-82 y) underwent 57 PET/CT scans. In 10 (91%) of 11 patients with Richter's transformation, PET/CT detected sites of abnormal 18F-FDG uptake having an SUVmax of greater than 5. Richter's transformation was missed in 1 patient who had only low-grade 18F-FDG uptake (SUVmax < 5). Nine patients had false-positive PET/CT findings; in 3 of these patients, alternative malignancies were diagnosed (Hodgkin's disease; metastatic neuroendocrine carcinoma; non-small cell lung cancer). In all remaining patients, PET/CT correctly excluded Richter's transformation. For the specific diagnosis of Richter's transformation of CLL to diffuse large B-cell lymphoma, PET/CT had overall sensitivity, specificity, and positive and negative predictive values of 91%, 80%, and 53% and 97%, respectively. CONCLUSION: PET/CT can detect Richter's transformation of CLL to diffuse large B-cell lymphoma with a high sensitivity and a high negative predictive value.     

^18F-FDG PET在原发性肾上腺淋巴瘤中的作用

目的探讨^18F—FDGPET（PET／CT）在原发性肾上腺淋巴瘤（PAL）中的作用。方法回顾性分析2005年10月至2009年8月确诊为PAL的3例患者。3例均为老年男性,双侧性NHL,治疗前均行超声、CT及PET（PET／CT）检查,并有组织病理学诊断资料。采用利妥昔单抗（rituximab）与环磷酰胺（cyclophosphamide）、表阿霉素（doxorubicin）、长春新碱（vincristine）、泼尼松（prednisone）组合（R—CHOP）方案化疗。治疗后1例进行了PET／CT的随访复查。^18F—FDGPET显像获得病灶SUVmax及与肝SUVmax的比值。结果3例均为双侧性弥漫大B细胞型PAL,骨髓穿刺阴性,R-CHOP方案化疗后,例1通过4次^18F—FDGPET复查随访、指导治疗,已存活1年7个月;例2伴有肾上腺皮质功能低下,6个月后死亡;例3年龄大（77岁）,病情重,手术部分切除后化疗,12个月后死亡。结论PAL虽然恶性程度极高,但如能早期诊断,并进行^18F—FDGPET疗效监测、修正治疗方案,可延长患者生存期。