Primary and secondary histiocytic lymphoma of the brain: CT features

The authors examined 19 patients with diffuse histiocytic lymphoma of the brain, including 8 with primary disease and 11 with secondary disease. Both primary disease and secondary disease involving the brainstem and deep nuclei exhibited the characteristic CT appearance, consisting of a large, solid, homogeneously enhanced mass with varying amounts of edema. However, most secondary lymphomas outside the brainstem and basal ganglia contained large areas of low attenuation consistent with necrosis. Multifocal lesions were seen only in patients with secondary lymphoma. Systemic chemotherapy for extracranial lymphoma had no effect on the CT appearance of intracranial lesions. The authors suggest that these "unusual" CT patterns are actually typical of a distinct subset of histiocytic lymphomas.     

小儿眼部恶性肿瘤的CT诊断

目的：总结分析小儿眼部恶性肿瘤的CT表现,提高影像诊断水平。方法：回顾性分析经过手术病理、临床证实的儿童眼部恶性肿瘤患者54例,分析其CT影像学改变。其中视网膜母细胞瘤41例,其它肿瘤13例,包括：白血病眼部浸润4例,横纹肌肉瘤3例,淋巴瘤2例,脉络膜黑色素瘤、恶性婴儿色素性神经外胚层瘤、转移性神经母细胞瘤、肌源性转移瘤各1例。结果：视网膜母细胞瘤以眼球内含有钙化的不规则肿块为明确的CT征象;其它肿瘤（如白血病的绿色瘤）多有不规则的生长方式以及周围骨质结构破坏而可以得出恶性肿瘤的诊断,结合临床资料可以得出相对准确的病理诊断;但是横纹肌肉瘤可因病变范围局限且境界清楚而恶性征象不明显。结论：在CT图像上,累及小儿眼部的大部分恶性肿瘤通常都有影像学的恶性征象,对定性诊断有重要的临床应用价值。     

CT evaluation of cardiophrenic angle lymph nodes in patients with malignant lymphoma

Two hundred seventy-four computed tomographic (CT) scans of the thorax were obtained in 209 patients with malignant lymphoma (153 Hodgkin disease and 56 non-Hodgkin lymphoma). Fourteen patients (6.6%) were shown to have adenopathy involving the cardiophrenic angle lymph nodes on CT. Of these, only three were considered positive on the basis of chest radiography alone. The anatomy of these diaphragmatic lymph nodes and CT appearance of these nodes when pathologically enlarged are discussed.     

Computed tomography of malignant lymphoma involving the skull

The CT findings in two patients with the unusual presentation of malignant lymphoma in the skull are described. The dominant CT findings were contrast enhanced large soft tissue masses without calcifications on both sides of the bone with very little or no changes in the bone itself. This characteristic CT appearance may be helpful to differentiate primary lymphoma of the skull from other bone tumors and osteomyelitis.     

Childhood leukemia: central nervous system abnormalities during and after treatment.

PURPOSETo document the radiologic abnormalities seen in the central nervous system (CNS) during and after treatment of childhood leukemia.METHODSMR images (19 patients) and CT scans (12 patients) were reviewed retrospectively in 19 children and adolescents with neurologic complications of leukemia or its treatment. Patients were divided into two groups: the first included those with disease-related complications of leukemia, such as meningeal and parenchymal leukemia, chloroma, and cerebrovascular disorders; the second included patients with treatment-related neurotoxicity and infection caused by immunocompromised states. Pathologic confirmation of the CNS lesions was obtained in eight patients. Factors that predisposed to the development of tumor-related or treatment-related complications were determined by reviewing the medical records.RESULTSAmong the 19 patients, 10 had two or more different CNS abnormalities found on CT scans or MR images. The imaging abnormalities seen in 12 patients during treatment included sinus thrombosis (n = 3), transient gray or white matter ischemia (n = 2), presumed disseminated microinfarcts (n = 1), cerebral hemorrhage or infarct (n = 3), inflammatory demyelinating polyradiculoneuropathy (n = 1), infections (n = 4, 2 bacterial and 2 fungal), and meningeal leukemia (n = 2). After therapy, seven patients had CNS imaging abnormalities, including secondary brain tumors (2 malignant gliomas and 1 CNS lymphoma), spinal chloroma (n = 1), necrotizing leukoencephalopathy and mineralizing microangiopathy (n = 3), cerebral mucormycosis (n = 1), spontaneous intracranial hemorrhage (n = 3), and spinal meningeal leukemia (n = 1).CONCLUSIONThe wide spectrum of CNS abnormalities that occur during and after treatment for leukemia is related to the inherent risk of the leukemia itself, to the treatment method, and to the duration of survival. Because many neurologic complications of leukemia are treatable, early diagnosis is essential.     

Paracardiac adenopathy: CT evaluation

To establish the normal CT appearance of lymph nodes in the paracardiac area, we reviewed the CT scans of 50 patients without known malignancy or benign causes of lymphadenopathy. Five patients (10%) showed soft-tissue densities in the paracardiac region. The largest of these measured 3.5 mm. No more than two rounded soft-tissue densities were seen in any of the normal CT studies. Forty-five patients with paracardiac adenopathy were subsequently evaluated. In 27 (60%) of these the masses were due to either carcinoma, sarcoma, or benign disease. In 40%, the cause of paracardiac adenopathy was lymphoma. Features that favor a diagnosis of lymphoma are bilateral disease, multiple nodes, nodes greater than 2 cm in diameter, a lobulated or "matted" appearance, and associated pericardial thickening/effusion. Chest radiographs obtained within 2 weeks of the CT scans in 38 patients revealed only nine cases in which a paracardiac mass could be seen. This study suggests that 1 cm is the upper limit for the diameter of lymph nodes in the paracardiac region, and that paracardiac adenopathy may be caused by a wide variety of nonlymphomatous malignant and benign diseases in addition to lymphoma. Compared with CT, chest radiographs are insensitive for detecting paracardiac lymph node enlargement.     

Third ventricular lymphoma: CT findings

Apparent intrathird ventricular masses were the only CT manifestations in four patients with central nervous system lymphoma. Involvement of the third ventricular region by lymphoma may not be as unusual as previously described in the literature. When lymphoma involves the third ventricle, its CT appearance may mimic other more common third ventricular masses.     

儿童眼眶转移性神经母细胞瘤和绿色瘤的特征性MR表现

目的 分析儿童眼眶转移性神经母细胞瘤和绿色瘤的特征性MR表现。资料与方法 回顾性分析经手术病理证实的9例儿童眼眶转移性神经母细胞瘤和5例绿色瘤的CT和MRI表现。所有病例均行CT平扫以及MRI平扫和增强扫描。结果 14例CT表现均为眼眶不规则肿块和邻近的眶壁溶骨性骨质破坏,7例骨质破坏区邻近的颅内可见扁平不规则肿块。2例转移性神经母细胞瘤表现为眼眶肌锥外间隙肿块内有与眶外壁垂直的针状高密度影。14例MRI表现为眼眶肌锥外间隙略长T1、略长T2信号不规则软组织影,7例骨质破坏区邻近的颅内硬膜外间隙可见略长T1、略长T2信号扁平不规则肿块,增强后明显强化。14例双侧眶骨及蝶骨大翼,9例斜坡和双侧岩尖及2例双侧颞骨鳞部骨髓腔脂肪高信号影被略长T1、略长T2信号影取代,采用脂肪抑制的增强T1WI显示均有强化,强化程度与眼眶内肿块相似。结论 儿童眼眶转移性神经母细胞瘤和绿色瘤的眶壁和颅面骨MR表现具有特征,有助于诊断和鉴别诊断。     

Non-Hodgkin's lymphoma of the appendix: clinical and CT findings with pathologic correlation

OBJECTIVE: The purpose of this report is to describe the clinical, CT, and pathologic features of non-Hodgkin's lymphoma of the vermiform appendix. CONCLUSION: Non-Hodgkin's lymphoma of the appendix typically manifests with acute symptoms in patients who have no prior history of lymphoma. Most patients with the disease present clinically with signs and symptoms suggestive of acute appendicitis. On CT, lymphomatous infiltration of the appendix produces markedly diffuse mural soft-tissue thickening (range of diameters, 2.5-4.0 cm; mean diameter, 3.2 cm). The vermiform morphology of the appendix is usually maintained, and aneurysmal dilatation of the lumen is sometimes seen. Stranding of the periappendiceal fat seen on CT may represent superimposed inflammation or even direct lymphomatous extension. Coexisting abdominal lymphadenopathy is not seen in all patients. Although appendiceal lymphoma is rare, the characteristic CT appearance could lead to a preoperative diagnosis.     

Computed tomography of gastrointestinal lymphoma

From 275 computed tomographic (CT) examinations with positive findings of abdominal lymphoma, 26 patients were found to have gastrointestinal involvement by the disease. The stomach was most commonly involved, followed by small bowel, colon, and duodenum. CT was found to be accurate in detecting wall thickening and complications such as perforation and fistulization. False-negative examinations occurred in two patients with small submucosal gastric deposits ("bull's-eye" lesions). False-positive examinations were seen in two patients with hypertrophic gastritis. The CT manifestations of gastrointestinal lymphoma, correlated with the barium study appearance, are the subject of this report.     

CT appearance of primary CNS lymphoma in patients with acquired immunodeficiency syndrome

Cranial CT studies of 32 patients with biopsy-proven AIDS-related primary CNS lymphoma were reviewed retrospectively. A wide variety of different CT appearances were identified. Mass lesions varied in location, size, and number. Most lesions were either iso- or hyperdense and all enhanced with contrast medium. Several different patterns of enhancement were observed. Mass effect and edema were seen in almost all patients. After radiotherapy, most tumors decreased in diameter, became hypodense, and no longer enhanced with contrast medium. Edema and mass effect decreased or resolved in all but one patient. Postradiotherapy CT scans also revealed interval enlargement of the ventricles and cortical sulci. This study demonstrates the wide diversity of CT appearances of AIDS-related primary CNS lymphoma. The CT findings cannot be used in lieu of biopsy for diagnosis of this disorder. The appearance of postradiotherapy CT scans was consistent with regressing lymphoma.     

Computed tomography of malignant lymphoma of the brain

Summary Correct diagnosis of malignant lymphoma of the brain and differentiation from malignant glioma, metastases, meningeoma and infection is often difficult. With the aim of finding characteristics pointing to the correct diagnosis all CT examinations from 16 patients with primary or secondary lymphoma of the brain were analysed. In 3 of 10 patients with primary lymphoma and 4 of 6 with secondary lymphoma the tumors were multiple. No differences between the CT appearance of primary and secondary lymphoma were found except that secondary lymphomas were generally smaller and more often multiple. The lymphomas were most often well demarcated, had a density equal to or slightly higher than normal brain tissue, were surrounded by no or slight edema and showed a moderate to marked contrast enhancement. The tumors were situated in the basal ganglia, corpus callosum or cerebellum in high frequency and were always in contact with either the ependyma of the ventricles or the superficial subarachnoid space. A tumor with widespread infiltration of the surroundings of the ventricles seen in 6 patients in the material is highly characteristic of lymphoma.     

Computed tomography of primary retroperitoneal malignancies

The CT examinations and medical records of 33 patients with primary retroperitoneal malignancies were reviewed. Computed tomography findings were then compared with those from scans performed on 122 patients with non-Hodgkin lymphoma who presented during the same time interval. Primary retroperitoneal neoplasms had three distinct CT appearances. Twenty-one patients (64%) had large soft tissue masses. Seven patients (21%) had masses with fatty density components, and five patients (15%) had tumors that were primarily of water attenuation. With the exception of those liposarcomas that contained recognizable fat, CT could not distinguish among the different cell types. Seventeen patients with non-Hodgkin lymphoma had large dominant retroperitoneal soft tissue masses that resembled primary retroperitoneal malignancies. In most cases, however, CT was able to differentiate these tumor masses from primary retroperitoneal tumors. Although 19 of 20 sarcomas of soft tissue attenuation were heterogeneous, only six of the 17 lymphomas presenting as dominant masses had such an appearance. Computed tomography is extremely helpful in initially evaluating patients with primary retroperitoneal tumors and in assisting the surgeon in planning his or her approach by accurately defining tumor extent.     

肺淋巴瘤的X线与CT诊断

目的 :研究肺淋巴瘤的X线与CT表现 ,提高对肺淋巴瘤的认识 ,减少误诊。材料和方法 :对 2 3例肺淋巴瘤进行胸部常规CT扫描 (15例 )及X线检查 (13例 ) ,全部病例均经各种活检或手术病理证实。结果 :肺淋巴瘤的影像学表现分为结节型、肺炎型、间质型、肿块型、粟粒型、混合型 ,其中以混合型最常见 ,占 60 9%。 16例伴有肺门、纵隔淋巴结肿大。CT对病灶的显示率明显高于X线。结论 :肺淋巴瘤的影像学表现多种多样 ,最常见为结节型与肺炎型并存 ,其次为结节型与间质型并存或肺炎型与间质型并存 ,常伴支气管气像 ,有一定特征性。CT优于X线     

Pulmonary mucosa-associated lymphoid tissue lymphoma: CT and pathologic findings

OBJECTIVE: The objective of this study was to determine the CT findings in pulmonary mucosa-associated lymphoid tissue lymphoma and to correlate these CT findings with histologic specimens. CONCLUSION: In the 11 patients reviewed, the most common CT appearance of pulmonary mucosa-associated lymphoid tissue lymphoma was consolidation with air bronchograms, correlating histologically with a cellular lymphocytic infiltrate expanding the interstitium and compressing adjacent alveoli, producing air bronchograms.     

PET/CT and renal pathology: a blind spot for radiologists? Part 2--lymphoma, leukemia, and metastatic disease

OBJECTIVE: PET/CT with (18)F-FDG is a powerful tool to evaluate patients with hematologic malignancy or to assess the burden of metastatic disease from solid tumors. Metabolically active renal pathology associated with lymphoma, leukemia, or metastatic disease can be missed without close attention to both the PET and CT portions of the study because of physiologic FDG excretion in the kidneys. This article illustrates the appearance of tracer uptake and the key anatomic features of lymphoma, leukemia, and metastatic disease involving the kidney on FDG PET/CT. CONCLUSION: Close attention to both the FDG PET and CT portions of an FDG PET/CT study is essential to evaluate the kidneys in oncology patients.     

Primary central nervous system lymphoma in AIDS: a wider spectrum of CT and MRI findings

Diagnosis of primary central nervous system lymphoma (PCNSL) in patients with AIDS based on radiological findings is still a challenging problem. Our purpose was to review the CT and MRI findings in PCNSL in our patients with AIDS and compare them with those reported in the literature. CT and MRI of 28 patients with AIDS and pathologically confirmed PCNSL were analysed retrospectively for the number of lesions, their site, size, density, signal intensity, contrast enhancement, oedema and mass effect. We found 82 lesions. On CT 45 lesions were found in 22 patients, whereas MRI revealed 66 in 20 patients. The lymphoma was solitary in 20 patients (29 %) and multiple in 20 (71 %). Spontaneous haemorrhage was seen in 7 patients. Contrast-enhanced MRI showed no enhancement in 27.3 % (18/66) of the lesions. In one patient diffuse signal abnormalities in the white matter were seen on T2-weighted images. Our findings suggest that the previously described spectrum imaging characteristics of PCNSL has widened. Neuroradiologists should be aware of the variable appearance in patients with AIDS. Spontaneous haemorrhage, a nonenhancing lesion, or diffuse white matter changes do not exclude lymphoma in an immunocompromised patient. Received: 25 January 2000/Accepted: 12 July 2000     

Non-Hodgkin's lymphoma of the bladder--CT and MRI appearances.

Computed tomography (CT) appearances of two patients with primary bladder non-Hodgkin's lymphoma are presented with magnetic resonance imaging (MRI) correlation in one. The differences between primary and secondary bladder lymphoma with respect to their clinical presentation, course and prognosis are described. Bladder lymphoma is a rare tumour which often presents as a large multilobular submucosal mass, and such an appearance may suggest the diagnosis. Bladder lymphoma, however, cannot be differentiated from the more common transitional cell carcinoma on the basis of CT attenuation values or enhancement patterns, or MRI signal characteristics. The diagnosis must, therefore, be made by histology. Other differential diagnoses and the role of various imaging techniques in the diagnosis and management of bladder lymphoma are considered.     

X-ray computed tomography in pathology of the greater omentum

CT examinations were reviewed in 19 patients with proved omental lesions (15 metastases, 1 lymphoma, 1 benign mesothelioma, 1 echinococcosis and 1 tuberculosis). Four distinct but aspecific patterns of omental pathology were identified with CT: omental caking; finely infiltrated fat with a "smudged" appearance; discrete nodules; cystic masses. CT is the most reliable radiographic technique to routinely evaluate omental lesions.     

Central nervous system lymphoma: histologic types and CT appearance

The distribution of histologic types of lymphoma according to the proposed working formulation was determined for 55 patients with primary central nervous system (CNS) non-Hodgkin lymphoma. Fifty-five percent of these patients had diffuse large-cell histologic features. When the relationship between histologic type and computed tomographic (CT) appearance was analyzed, the following trends were noted: A greater percentage of mixed cell tumors were multiple when compared with other types; noncleaved small-cell tumors were more commonly located in the central gray matter or corpus callosum than were other types; all immunoblastic tumors were enhanced homogeneously, unlike other types; and smaller tumors appeared to be associated with an increased histologic grade. Eleven patients had CT confirmation of a CNS recurrence; in eight patients, the recurrent tumor was in a different location than the original lesion. Eleven patients had associated intraocular lymphoma, and four were immunosuppressed.