Central nervous system involvement of leukemia and systemic lymphoma in children: CT and MR findings

The purpose of this paper is to retrospectively evaluate CT and MR findings of central nervous system (CNS) involvement of leukemia and systemic lymphoma in children. Over a 12-year period, sixty-five patients with leukemia and fifteen patients with systemic lymphoma underwent cerebral CT and/or MR imaging. Nine patients (11.3%) were diagnosed as CNS involvement of leukemia and lymphoma. The diagnostic criteria of CNS involvement were as follows; 1) Histological proof was confirmed by surgery, 2) Tumor cells were found in the cerebrospinal fluid examinations, 3) Increase in size of the lesion during observation without specific treatment, and 4) Response to the treatment for leukemia or lymphoma. All of nine patients fulfilled more than two criteria of 1)-4). The CT and MR abnormalities in these patients were correlated with the findings of histology, cerebrospinal fluid cytology, and/or treatment. The age of the patients ranged from 0 to 15 years old. They consisted of 6 boys and 3 girls. The CT examinations were performed before and after contrast administration. MR examinations were performed on a 1.5-T unit, and T1-weighted, T2-weighted, and proton density-weighted images were obtained using spin-echo or fast spin-echo sequences. Tumor masses were present in seven with leukemia (acute lymphoblastic leukemia 4; acute myeloblastic leukemia 1; acute promyelocytic leukemia 1; acute monocytic leukemia 1), and in two with malignant lymphoma. On the CT scan, tumor masses were hyperdense with contrast enhancement. On the MR images, their signals were variable. In all of nine patients, tumor masses were contiguous with a meningeal surface. Postcontrast T1 weighted images were valuable in demonstrating meningeal infiltration. Tumoral hemorrhage was found in two patients. In a patient with tumor at the superior sagittal sinus, venous infarct was observed. CNS leukemic and lymphomatous masses are almost hyperdense on the CT and they are characteristically contiguous with a meningeal surface. MR imaging was valuable in demonstrating meningeal infiltration. Findings of CT and MR imaging, cerebrospinal fluid examinations, and response to the treatment are useful in the differentiation of CNS involvement of leukemia and lymphoma from other lesions such as infectious diseases and leukoencephalopathy.     

Simultaneous progressive multifocal leukoencephalopathy, Epstein-Barr virus (EBV) latent infection and cerebral parenchymal infiltration during chronic lymphocytic leukemia

We report a non-HIV patient who had B chronic lymphocytic leukemia (CLL) with progressive multifocal leukoencephalopathy (PML) and diffuse cerebral leukemic parenchymal infiltration in the presence of JC virus and Epstein-Barr virus (EBV) cerebral co-infection. Multiple subcortical hypodensities lining the cortico-subcortical junction were present within the white matter on computerized tomography (CT) scan, with large areas of high signal intensity on T2-weighted sequences on magnetic resonance imaging (MRI). JCV DNA was identified in peripheral blood nuclear cells and cerebrospinal fluid polymerase chain reaction (PCR) DNA/DNA hybridization plus Southern blot analysis. Frontal stereotactic biopsy confirmed the diagnosis of PML by immunocytochemistry, in situ hybridization (ISH) with JC Enzo probe and electron microscopy. Leukemic B cells with the same phenotype as leukemic blood cells were disseminated in the demyelinated areas. They were labeled by anti-latent membrane protein and by BamHl W EBV probe after ISH. Adhesion and activation molecules were positive for CD23. Autopsy showed diffuse visceral leukemic infiltration without acutization. EBV-transformed B lymphocytes would favour JCV penetration and/or intracerebral reactivation of previously latent JCV infection with further development of simultaneous PML and cerebral CLL infiltration in an immunosuppressed patient.     

Central nervous system involvement at presentation in acute granulocytic leukemia. A prospective cytocentrifuge study

We have undertaken a perspective study of the prevelance of the central nervous disease in acute granulocytic leukemia (AGL). Thirty-nine newly diagnosed patients with AGL underwent cytocentrifuge examination of cerebral spinal fluid. Seven of the 39 patients had blast cells in their cerebral spinal fluid. All seven of these patients had acute myelomonocytic leukemia (AMML). No patients with other variants of AGL demonstrated blast cells in their cerebral spinal fluid. Other high risk factors associated with meningeal infiltration were elevated serum lysozyme levels, high peripheral white blood cell count, low age, splemomegaly and the presence of infiltration in other organs. The admission rates for patients with meningeal leukemia were lower and the survival time was shorter than in both the 32 noninvolved patients and the noninvolved patients with AMML. We believe that a lumbar puncture is indicated in all patients with newly diagnosed AMML.     

An experimental model for meningeal leukemia in rats (L5222). Effect of treatment with BCNU and cyclophosphamide

An experimental model of meningeal leukemia in rats is developed by intracerebral (IC) inoculation of leukemic cells from the transplantable acute leukemia L5222. The L5222 proliferates exponentially in the central nervous system (CNS) and the disease becomes systemic 2 days following IC inoculation. Chemotherapeutic studies with BCNU and cyclophosphamide yielded cures in a high percentage of cases when treatment began at an early stage of meningeal leukemia. When treatment was started at the advanced stage, only BCNU showed a large number of cures. However, cyclophosphamide resulted in a marked increase of life-span. The activity of cyclophosphamide against meningeal leukemia, which is in contrast to the results obtained by Skipper et. al. (1961) in the L1210 mouse leukemia, suggests that cyclophosphamide crosses in part the blood--brain barrier in a rat bearing meningeal leukemia. After subcutaneous inoculation, BCNU and cyclophosphamide showed the same rate of cures.     

Gadolinium and contrast medium MRI of the acoustic nerve in patients with meningeal neuritis and acoustico-facial syndrome

Twelve cases of vestibular neuritis were investigated in gradient echo MRI with gadolinium. Only 3 severe cases associated with an acoustico facial syndrome (2 cases of herpes zoster oticus and one case after influenzae) demonstrated focal enhancement within the internal auditory canal on post contrast T1 weighted images. This enhancement involved at least 2 differents nerves. These 3 severe cases associating sensory neural hearing loss and facial palsy revealed a meningeal reaction after cerebrospinal fluid examination. The enhancement lasted a long time (up to 10 months) in one case of RAMSAY HUNT syndrome associated with a chronic lymphocytic leukemia. The MRI was able to confirm the anatomical reality of the vestibular neuritis and more precisely of the meningoneuritis and gave arguments for the theory of the polyneuropathy of Adour. Enhancement at MRI seems correlated with the severity of the affection (permanent vestibular areflexia in 3 cases and permanent hearing loss in 1 case).     

Sphenoethmoidal mucoceles with intracranial extension--three case reports

Three unusual cases of sphenoethmoidal mucoceles with rare intracranial extension are reported. A 64-year-old female presented with a 7-month history of right visual disturbance. Computed tomography (CT) and magnetic resonance (MR) imaging demonstrated a huge mass in the right middle fossa. She underwent right frontotemporal craniotomy. Postoperatively, her proptosis and cranial nerve dysfunction had improved markedly. A 53-year-old female complained of headache, nausea, and dizziness. CT and MR imaging revealed a cystic mass filling the right sphenoid sinus. The cystic lesion was evacuated through the transnasal approach. She was doing well postoperatively and has been asymptomatic. A 39-year-old male complained of headache, vomiting, and right visual disturbance. CT and MR imaging demonstrated a homogeneous mass occupying the sphenoid sinus. Sphenoidotomy exposed the cyst extending superiorly into the anterior cranial fossa. He recovered from the visual disturbances and has been asymptomatic since. MR imaging provides confirmation of the diagnosis of sphenoethmoidal mucocele and is important for preoperative evaluation.     

Infrahyoid neck

Imaging is an indispensable tool in patients with clinical suspicion of infrahyoid neck disease. CT and MR imaging can establish a positive diagnosis by showing a true mass (versus a pseudomass). In addition, by defining the exact space of origin of the lesion and its characteristics (CT density, MR signal, homo- or heterogeneity, contour, contrast enhancement), imaging can predict the correct diagnosis. Because it offers multiplanar, multiparameter information, MR imaging, performed with a dedicated coil and appropriate artifact-reduction techniques, usually is the modality of choice.     

Magnetic resonance imaging of renal lymphoma with computed tomography correlation

The magnetic resonance (MR) imaging and computed tomography (CT) findings in four patients (five kidneys) with non-Hodgkin's lymphoma involving the kidneys and perirenal spaces are presented. The patterns of disease in each case were as follows: bilateral renal nodules, infiltration in the perirenal space, infiltration in the perirenal space with renal involvement, and direct invasion from contiguous retroperitoneum. On plain CT, the lesions showed slight hyperdensity (three kidneys) and isodensity (two kidneys) as compared with normal renal parenchyma. But all lesions appeared as hypodense masses with more definite margins after contrast enhancement. MR imaging findings showed iso- or slight hypointense masses on T1-weighted images and definite hypointense masses on T2-weighted images as compared with the signal intensity of the renal cortex. Dynamic imaging and conventional delayed T1-weighted imaging following Gd-DTPA injection showed no significant enhancement of the lesions. In comparison with contrast enhanced CT, despite its poorer resolution, T2-weighted MR imaging showed nearly the same accuracy in the evaluation of number and extent of the lesions without contrast medium administration. MR imaging was also useful to evaluate the patency of vessel lumen surrounded by tumor mass and to determine the location and extent of huge lesions by its multiplanar imaging capabilities.     

Imaging approach to the diagnosis of pulmonary sequestration

PURPOSE: To describe the characteristic features of pulmonary sequestration (PS), to evaluate the usefulness of various imaging modalities, and to find a rational approach to accurate diagnosis. MATERIAL AND METHODS: Twenty-four patients with PS proved by operation and pathology were reviewed retrospectively. Plain chest films were done in all patients, bronchography in 3, sonography in 14, CT in 6 (including CT angiography in 1 case), MR in 8 (including MR angiography in 1 case) and aortography in 12 (including DSA in 1 case). RESULTS: Plain chest films demonstrated a solid mass in 14 patients and a cystic mass in 10. Bronchograms showed displacement of adjacent bronchi with no filling of contrast medium within the lesion in 2 cases, while another case had a blind intermediate portion of the right bronchus (hypoplasia of middle and lower lobes associated with extralobar sequestration). Sonography demonstrated a solid lung mass in 12 cases and a solid mass with cystic areas in 2, and detected vessel-like structures within the mass or in its surroundings in 12. Doppler analysis showed arterial spectral wave confirming a feeding artery. CT revealed a solid mass in all patients, a mass with low density area in 4, and emphysema surrounding the mass in 3. MR imaging depicted anomalous arteries in all patients and venous drainage in 4 cases. Aortography demonstrated anomalous systemic arterial supply to the PS in all patients. In this series, 21 cases (87.5%) were correctly diagnosed preoperatively by the imaging modalities. CONCLUSION: Plain chest films can provide a diagnostic clue to PS. Sonography, CT and MR are helpful for showing arterial blood supply and for making a definite diagnosis. We recommend a rational imaging approach for the diagnosis of PS.     

Primary muscle lymphoma: clinical and imaging findings

PURPOSE: To assess the clinical and imaging findings in primary muscle lymphoma. MATERIALS AND METHODS: Seven patients with biopsy-proved primary muscle lymphoma without evidence of systemic disease underwent imaging with plain radiography or computed tomography (CT) and magnetic resonance (MR) imaging. Four underwent bone scintigraphy, and two underwent gallium scintigraphy and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) before and after therapy. RESULTS: Plain radiographs at initial examination (n = 5) showed no bone abnormalities. Soft-tissue masses and bone marrow involvement showed isoattenuation at CT (n = 3), but at MR imaging (n = 7), all masses demonstrated increased signal intensity on T2-weighted images that involved multiple muscle compartments and typically spanned a long segment of the extremity. Adjacent bone disease was less extensive than muscle disease, and, in most cases, subcutaneous stranding or extension was observed adjacent to the masses. Good size correlation was observed between findings at MR imaging, gallium scintigraphy, and FDG PET. Two patients developed recurrent multifocal muscle lymphoma several years after initial examination. CONCLUSION: The presence of an extensive soft-tissue mass with infiltration of adjacent subcutaneous fat and minimal or no extension into the bone marrow cavity at MR imaging and normal plain radiographic findings may suggest primary muscle lymphoma.     

The accuracy of CT and MR evaluation of the sella turcica for detection of adrenocorticotropic hormone-secreting adenomas in Cushing disease

PURPOSE: To document the accuracy of CT and MR of the sella turcica for detecting adrenocorticotropic hormone-secreting adenomas in Cushing disease. METHODS: The radiologic findings of the sella turcica prior to transsphenoidal surgery are reviewed in 141 patients who had biochemical evidence of pituitary-dependent Cushing disease. Axial thin-collimation CT scans with sagittal and coronal reformations before and after contrast enhancement were obtained in 125 patients. Seventy-eight patients had MR examinations with a 1.5-T superconducting magnet. In 11 of the patients gadolinium-enhanced MR scans were also obtained. The preoperative interpretation of the imaging studies was correlated with the surgical findings and patients follow-up. RESULTS: The sella turcica was enlarged in 43 cases (30%). In 125 patients reformatted or direct coronal thin-collimation CT scans were available. Seventy-eight of the patients had MR. In the 12 patients with pituitary macroadenomas, the accuracy of CT (n = 10) and MR (n = 10) in respect to detection of the lesion was 100%. Of the 98 microadenomas assessed by CT, 47 (48%) were directly depicted as distinct hypodense lesions. In only 31 of 73 cases (42%), however, could CT predict the precise anatomic location and extent of the lesions. Only patients in whom the hypercortisolism was corrected by later surgery were considered for the correlation analysis. Of the 52 microadenomas assessed by MR, 28 (53%) were directly depicted as distinct lesions of reduced signal intensity on T1-weighted images, and in only 21 of 41 cases (52%) did MR show good correlation to the surgical findings. Some degree of partially empty sella was found in 22% of the patients. CONCLUSIONS: Although both the sensitivity and the diagnostic accuracy of imaging methods of the sella turcica have been considerably improved in comparison with previous reports, they still provide only a minor contribution to the diagnosis and differential diagnosis of Cushing syndrome.     

Necrotic malignant melanoma of the choroid and concurrent intraocular manifestation of malignant non-Hodgkin's B cell lymphoma

An 80-year-old white female developed clinical signs of a large choroidal malignant melanoma in her left eye. There were no signs of metastatic disease, but an asymptomatic chronic lymphatic leukemia was discovered. Histopathologic examination of the enucleated left eye showed a mostly necrotic malignant melanoma of the choroid with areas of spindle B cell differentiation, episcleral extension and secondary angle-closure glaucoma with necrosis of the anterior segment of the eye. On the basis of immunocytochemical studies of the lymphocytic infiltrates in the iridal blood vessels, retinal blood vessels and the choroid, the leukemic disease was classified as B cell lymphoma of low malignancy (lymphoplasmacytoid immunocytoma). A reactive T lymphocytic infiltration of the conjunctival stroma was also noted. Patients with malignant melanomas of the uvea require exclusion of a second malignancy.     

Increased sensitivity of acute myeloid leukemias to lovastatin-induced apoptosis: A potential therapeutic approach

We recently demonstrated that 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme of de novo cholesterol synthesis, was a potential mediator of the biological effects of retinoic acid on human neuroblastoma cells. The HMG-CoA reductase inhibitor, lovastatin, which is used extensively in the treatment of hypercholesterolemia, induced a potent apoptotic response in human neuroblastoma cells. This apoptotic response was triggered at lower concentrations and occurred more rapidly than had been previously reported in other tumor-derived cell lines, including breast and prostate carcinomas. Because of the increased sensitivity of neuroblastoma cells to lovastatin-induced apoptosis, we examined the effect of this agent on a variety of tumor cells, including leukemic cell lines and primary patient samples. Based on a variety of cytotoxicity and apoptosis assays, the 6 acute lymphocytic leukemia cell lines tested displayed a weak apoptotic response to lovastatin. In contrast, the majority of the acute myeloid leukemic cell lines (6/7) and primary cell cultures (13/22) showed significant sensitivity to lovastatin-induced apoptosis, similar to the neuroblastoma cell response. Of significance, in the acute myeloid leukemia, but not the acute lymphocytic leukemia cell lines, lovastatin-induced cytotoxicity was pronounced even at the physiological relevant concentrations of this agent. Therefore, our study suggests the evaluation of HMG-CoA reductase inhibitors as a therapeutic approach in the treatment of acute myeloid leukemia.     

Cerebral gumma showing linear dural enhancement on magnetic resonance imaging--Case report

A 51-year-old male presented with a rare cerebral gumma accompanied by abducens nerve paresis and cerebellar infarction. Magnetic resonance (MR) imaging demonstrated a homogeneous enhance mass lesion and adjacent linearly enhanced dura mater. Histological examination of the mass revealed a caseating granuloma. Serological studies were positive for active syphilis. Although linear dural enhancement adjacent to the mass lesion on MR imaging is characteristic of meningioma, this finding is also demonstrated in cerebral gumma. Therefore, cerebral gummas should also be included in the differential diagnosis. Immunological tests for syphilis (serum, cerebrospinal fluid) can confirm the diagnosis.     

A case of brain abscess accompanied with sudden-onset hemiplegia as initial manifestation

A 58-year-old male experienced a sudden stroke-like onset of right hemiplegia and numbness of his right upper limb while engaged in his desk-work on April 7, 1997. He had a past history of diabetes mellitus and hyperlipidemia. On admission, he had no fever and the blood pressure was 140/70 mmHg. General physical examination was unremarkable. Neurological examination showed 4/5 strength of his right unilateral extremities and numbness of his right upper limb. Clinical features and computed tomography (CT) without contrast medium at the onset of hemiplegia suggested a stroke. Seven days after admission, his consciousness worsened and body temperature fluctuated between 37 and 38 degrees C. Subsequent Gd-enhanced magnetic resonance (MR) which demonstrated an irregular shaped ring-enhancement lesion and lumbar puncture 9 days after admission was compatible with the diagnosis of brain abscess. Surgical drainage confirmed the presence of brain abscess due to alpha-streptococcus. It improved following surgical drainage and antibiotic therapy with PAPM.BP 2 g/day and PIPC 4 g/day. An afebrile patient of sudden stroke-like onset may be a rarity to be added to the differential diagnosis of brain abscess.     

Chromosomes and causation of human cancer and leukemia. XLVIII. T-cell acute leukemia in ataxia telangiectasia

Cytogenetic and immunologic studies were performed on the cells of an 18-year-old female with ataxia telangiectasia (AT) associated with acute lymphocytic leukemia (ALL). At the onset of the leukemia 15.4% of peripheral blood cells stimulated with phytohemagglutinin (PHA) contained a tandem translocation of the long arm of chromosome #14, i.e., t(14;14). To ascertain if these karyotypically abnormal cells and the leukemic cells had a common lineage, chromosome analyses were performed on bone marrow cells. Examination of the marrow cells on the seven occasions when leukemic cells were present in the marrow, including times when they were predominant, showed only a normal karyotype without the presence of t(14;14). However, an abnormal clone, which had the karyotype 45,XX,-9,t(9;6)(q12;q13), was identified in the marrow cells on the last examination during the terminal phase of the leukemia. Immunologically, the ALL was classified as an atypical type which had characteristics in common with certain T-cell subsets. We suggest that the malignant cells did not originate from the preexisting cells with a tandem duplication of the 14q.     

Efficacy of gadolinium in MR brain imaging of HIV-infected patients

PURPOSE: To determine the value of gadolinium in routine head MR imaging of HIV-infected patients. METHODS: One hundred and three consecutive human immunodeficiency virus-infected patients referred for head MR imaging were scanned without and with intravenous gadopentetate dimeglumine (Gd-DTPA) contrast. RESULTS: The precontrast scans of 82 patients were either normal, or had atrophy or diffuse white matter changes only. Sixteen of these 82 demonstrated enhancing abnormalities: eight meningeal/ependymal enhancement and eight focal enhancing lesions. Twenty-one of the 103 scans had focal or mass lesions on the precontrast images; in eight of these scans, new information was obtained with Gd-DTPA. Of the 24 patients in both groups where new information was obtained with Gd-DTPA, the information contributed to a change in the clinical care of nine patients. CONCLUSION: Gadolinium-enhanced MR is useful in the management of selected patients with human immunodeficiency virus infection, for example those with symptoms suggesting meningeal involvement, focal brain lesions, or if the unenhanced MR does not explain all the patient's symptoms.     

Role of endorectal ultrasonography and CT in preoperative staging of rectal cancer. Personal experience]

We report our personal experience on endorectal US and CT in the preoperative staging of rectal carcinoma. Our series includes 64 cases (38 male and 26 female) evaluated with intrarectal sonography; 38 of these patients underwent also CT-study of the lower abdomen. Using both imaging techniques infiltration of the rectal wall and adjacent structures and lymph node involvement were studied. The results of our study refer to 58 patients who underwent endorectal US, 31 of whom studied also with CT. Referring to the T-parameter with ultrasound 41 correct diagnosis were obtained, in 13 cases the lesion was over-staged and in 4 cases understaged. The sensitivity, specificity and diagnostic accuracy was respectively 89.5%, 60% and 79.3%. With CT 23 diagnosis were correct, in 1 case the lesion was overstaged and in 7 cases understaged; sensitivity, specificity and diagnostic accuracy concerning rectal wall infiltration were respectively 72%, 83.3% and 74.2%. The evaluation of the N-parameter demonstrated low value of sensitivity with both US (15.8%) and CT (42.9%). Considering the results of our series, we feel that it is necessary to use both imaging techniques because results obtained are complementary referring to the T-parameter, although N-parameter were a little significant.     

MR images of mycobacterial infection

With the progress of imaging technologies such as CT and MR imaging, we can obtain various informations from CT and MR images. Especially, thin-section high resolution CT (HRCT) provides very useful information for the diagnosis of mycobacterial infection and other diseases of pulmonary parenchyma. Advantages of MR images over HRCT are higher tissue contrast and multidirection capability. The T2-weighted images and Gd-DTPA enhanced T1-weighted images accurately reflect pathologic structure of the lesion. Therefore, MR images can add many useful findings to CT on the selected cases which are differentiation of tubercloma from lung cancer, chronic empyema from mesothelioma, aspergiloma from lung cancer and lymphadenopathy from lymph node metastasis. We describe the usefulness of MR images for diagnosing mycobacterial infection and its differentiation from other pulmonary diseases.