Long-term outcome of hypothalamic pituitary tumors in Langerhans cell histiocytosis

BACKGROUND

Hypothalamic-pituitary (HP) disease is the most common CNS manifestation of Langerhans cell histiocytosis (LCH) frequently leading to diabetes insipidus (DI) and anterior pituitary hormone deficiencies (APD). On MRI, loss of the normal posterior pituitary signal and thickening of the pituitary stalk have been described, as well as neurodegenerative signal changes associated with neuropsychological disabilities in some patients. The influence of therapy on the long-term course of HP tumors and neurodegeneration (ND) is not well-understood.

PROCEDURE

In this retrospective survey we focused on patients with LCH and HP disease with clinical and MRI data available at diagnosis of HP disease and at least three follow up investigations. We collected clinical and MRI follow-up information for central review and analysis.

RESULTS

We identified 22 patients with HP tumors (HPT) registered at the LCH study center. Many different treatment regimens were applied for variable periods, with more than one regimen in most patients. Regression of the tumor was seen in the majority, but all patients had APD or ND on MRI at last follow up. In none of the patients APD and ND regressed or resolved. A deterioration of radiological ND was noted in 17 patients leading to overt clinical neuropsychological impairment in five.

CONCLUSIONS

Patients with HPT appear to be at high risk to develop permanent neuroendocrine consequences. Coordinated studies for patients with LCH and HP disease including thorough MRI monitoring and neuropsychological tests are needed.

Incidence and pattern of radiological central nervous system Langerhans cell histiocytosis in children: a population based study

BACKGROUND

Patients with Langerhans cell histiocytosis (LCH) may develop neurodegeneration and other central nervous system (CNS) dysfunctions revealed by brain magnetic resonance imaging (MRI). We estimated the incidence and pattern of pathological brain MRI findings in a well-defined, population-based cohort of children with LCH.

METHODS

Among children under 15 years of age diagnosed with LCH in the Stockholm County during 1992-2001, brain MRI was performed at a single center in children with clinical and/or laboratory signs of CNS involvement, including endocrine dysfunction.

RESULTS

Out of the 29 children (16 males, 13 females) diagnosed with LCH, brain MRI was performed based on clinical indications in 16 children (55%) with either abnormal endocrine findings (n = 6), such as diabetes insipidus (n = 5), low IGF-1 (n = 1), or panhypopituitarism (n = 1), or clinical CNS symptoms (n = 10). CNS MRI abnormalities were demonstrated in eight children (28%), at a median time of 3.5 years after LCH diagnosis (range 1-11.4 years). Altogether 7 of the 29 children (24%) had MRI findings associated with neurodegeneration, corresponding to a minimal incidence of 2.1/10(6) children per year. Neurodegenerative abnormalities tended to be more frequent in patients with craniofacial involvement (P = 0.12).

CONCLUSIONS

The minimal annual incidence rate of neurodegenerative associated radiographic findings in LCH is estimated at 2.1/10(6) children (24% of all children with LCH). An important question is whether all patients with LCH, or certain forms of LCH, should be recommended for a late follow-up examination including MRI. In patients with CNS-LCH, neurological, neuropsychological, neurophysiological, neurochemical and neuroradiological follow-up assessment is suggested.

2'-Chlorodeoxyadenosine (2-CdA) as salvage therapy for Langerhans cell histiocytosis (LCH). results of the LCH-S-98 protocol of the Histiocyte Society

BACKGROUND

A prospective phase II Histiocyte Society study, LCH-S-98, evaluated the efficacy of 2-chlorodeoxyadenosine (2-CdA) monotherapy as salvage therapy in Langerhans cell histiocytosis (LCH).

PROCEDURES

Patients with poor and intermediate risk LCH not responsive to initial therapy and patients with low-risk chronic recurrent LCH were evaluated for response and survival after treatment with 2-6 courses of 2-CdA.

RESULTS

Forty-six patients (55%) had involvement of risk organs; lung, liver, spleen, or hematopoetic system (RO+), 37 (45%) were RO-. Twenty-two percent of RO+ patients had a good response while 44% progressed, 62% RO- patients responded, and 11% progressed. Two-year predicted survival is 48% for RO+, 97% for RO- patients, 100% for RO+ patients reactivating in non-risk organs, 67% for RO- patients reactivating in risk organs. Two-year pSU for the entire group is 68%. Seventy-three percent of patients with a poor response to 2-CdA died. Sixty-five percent patients >2 years old and 30% <2 years old survived. There was a median of 26 months from diagnosis to 2-CdA for responders compared to a median of 5 months for non-responders. Twenty-one percent of patients treated <12 months and 57% treated >12 months from diagnosis responded.

CONCLUSION

2-CdA is active in LCH. It produces a higher response rate in patients with low-risk multisystem or multifocal bone disease than those with risk organ involvement. "Risk" patients who fail to respond to 2-CdA have a high mortality. Patient age at 2-CdA therapy and length of time from diagnosis to 2-CdA significantly affect response and survival.

Reactivations in multisystem Langerhans cell histiocytosis: data of the international LCH registry

OBJECTIVE

To assess multisystem Langerhans cell histiocytosis reactivation and its impact on morbidity and mortality.

STUDY DESIGN

Retrospective analysis of 335 patients with MS-LCH and documented complete disease resolution (NAD1).

RESULTS

The probability of a reactivation within 5 years of NAD1 was 46%. The first reactivation occurred within 2 years after NAD1 in most of the patients. Of 134 events, 35% were confined to skeleton, 24% were single-system nonbony lesions, 24% were multisystem reactivations without risk-organ involvement, and 10% with risk-organ involvement. In 7%, the location was unspecified. Only 3 deaths (2.2%) were documented within the context of a first reactivation. Second disease resolution (NAD2) was achieved in 85% of the cases. The probability of a second reactivation within 5 years of NAD2 was 44%. The risk for permanent consequences in patients with reactivations was higher, compared with patients without reactivation (RHR 2.2, P = .046).

CONCLUSIONS

Reactivation is a frequent and early event in MS-LCH, but involvement of risk organs at reactivation is rare and mortality is minimal. However, reactivations increase the risk for permanent consequences by about 2-fold. Prospective trials targeting reduction of acute morbidity and permanent disabilities through nontoxic treatment of the reactivations are warranted.

Bone marrow assessment in Langerhans cell histiocytosis

BACKGROUND

Bone marrow changes and their relation to blood cytopenia in patients with Langerhans cell histiocytosis (LCH) have not been extensively studied to date. The aim of the present study was to characterize the bone marrow changes in LCH patients and to ascertain their relation to disease severity.

METHODS

Fifty-seven marrow samples of LCH patients were studied by conventional cytology, immunocytochemistry (ICC) and flow cytometry (FCM).

RESULTS

On conventional cytology there was no significant difference between LCH cases and controls with respect to cellularity, number of monocytes and progenitor cells, and presence of histiocytes and hemophagocytosis. The numbers of nucleated cells, CD34(pos) cells, and CD14(pos) cells on FCM did not differ, either. The CD1a staining by ICC was positive in 14/41 LCH samples, and was consistently negative in controls. FCM staining for CD1a was positive in 12/54 samples, but also in 5/35 controls. The number of the CD1a(pos) cells in LCH marrows was usually very low (<10-20 cells/slide by ICC, or <0.5% of the leukocytes by FCM). The CD1a staining was more frequently positive and more pronounced in patients with severe disease.

CONCLUSIONS

The combination of conventional aspirate cytology with ICC (CD1a staining) appears to be the most reliable tool for bone marrow assessment in LCH.

Long-term MR imaging course of neurodegenerative Langerhans cell histiocytosis

BACKGROUND AND PURPOSE

MR imaging signal intensity abnormalities in the cerebellum, the pons, and the basal ganglia, compatible with a neurodegenerative process (ND) were reported in up to 10% of patients with Langerhans cell histiocytosis (LCH). Although the imaging features of ND-LCH have been extensively described, the temporal course of ND-LCH has not been assessed as of yet. The purpose of this study was to describe the long-term course of MR imaging signal intensity abnormalities in ND-LCH on T1- and T2-weighted images.

MATERIALS AND METHODS

In this retrospective study, 9 patients with ND-LCH with an observation time of at least 5 years were included. Three or more MR imaging studies per patient, performed in 3-year intervals (+/-11 months), were reviewed. Signal intensity abnormalities on T1- and T2-weighted images in the cerebellum, the pons, and basal ganglia were scored for their signal intensity quality and their extension. In addition, the severity of cerebellar atrophy was scored.

RESULTS

The signal intensity alterations were not resolved in any of the patients. Instead, a progression of the signal intensity alterations either in the cerebellum or basal ganglia was observed in all of the patients but did not correlate with a clinical deterioration. Overt and severe neurologic symptoms were reported in only 2 patients in whom some form of atrophy was noted.

CONCLUSIONS

ND-LCH appears to be a slowly progressive process. The increase of signal intensity abnormalities in the cerebellum and basal ganglia does not correlate with neurologic deterioration. MR imaging appears to be a sensitive technique to detect and monitor radiologic ND-LCH.

Central nervous system-related permanent consequences in patients with Langerhans cell histiocytosis

BACKGROUND

Permanent consequences in Langerhans cell histiocytosis (LCH) are irreversible late sequelae related to the disease that may severely impair the quality of life of survivors. The frequency and pattern of permanent consequences affecting the central nervous system (CNS) remains to be determined.

PROCEDURE

In this single center study, 25 LCH patients observed for a median time of 10 years 3 months underwent a uniform thorough follow-up program including neuropsychological testing and electrophysiological evaluation.

RESULTS

Overall permanent consequences were seen in 9 of 25 patients. Intracranial abnormalities were the most frequent including diabetes insipidus (DI) in seven patients, anterior pituitary deficiencies in five patients, and neurodegenerative CNS disease in five patients. No patient had overt neurological symptoms upon neurological evaluation, but psychological testing revealed subtle deficits in short-term auditory memory (STAM) in 14 patients. Brain stem evoked potentials showed abnormalities in four of nine tested patients, all of these four had neurodegeneration on MRI.

CONCLUSION

Psychoneuroendocrine sequelae were found in an unexpectedly high number of patients in this single center study. Long-term follow-up focusing on such sequelae are important in LCH survivors, in order to detect early deficits, to monitor the evolution of the disease, and to provide specific support.

Central diabetes insipidus: Is it Langerhans cell histiocytosis of the pituitary stalk? A diagnostic pitfall

Central diabetes insipidus (CDI) is a rare disorder that may be caused by a variety of diseases. In pediatric and adolescent patients the most common causes for CDI are Langerhans cell histiocytosis (LCH) and germinoma. To avoid a potentially hazardous biopsy of the hypothalamic pituitary region it is recommended to evaluate patients with CDI carefully to identify potential extracranial lesions. Since LCH is the most common systemic disease that may cause CDI, special focus is paid to the identification of LCH lesions. We report on a 9(1/2) year old girl who presented with central diabetes insipidus and a thickening of the pituitary stalk on magnetic resonance imaging. Diagnostic workup revealed a history of recurrent ear infections and a compressed 6th thoracic vertebral body on radiographs. Based on these findings LCH was anticipated. Upon growth of the pituitary stalk lesion the patient was treated with LCH standard chemotherapy. After an initial shrinkage of the lesion, a further growth of the pituitary stalk lesion was observed and the tumor was resected. Histopathology revealed germinoma. This case underscores the importance of a istopathologically proven diagnosis in patients with HPR tumors before the initiation of a specific therapy, even if the clinical findings are highly suggestive.

Risk factors for diabetes insipidus in langerhans cell histiocytosis

BACKGROUND

Diabetes insipidus (DI) is the most frequent central nervous system (CNS)-related permanent consequence in Langerhans cell histiocytosis (LCH), which mostly requires life-long hormone replacement therapy. In an attempt to define the population at risk for DI, 1,741 patients with LCH registered on the trials DALHX 83 and DALHX 90, LCH I and LCH II were studied.

RESULTS

Overall 212 of 1,741 patients (12%) was reported to have DI. In 102 of 1,741 patients (6%) DI was present at diagnosis of LCH. One thousand one hundred eighty three of 1,539 patients without DI at diagnosis had follow up information. One hundred ten of these (9%) later developed DI. The risk of developing DI was 20% at 15 years after diagnosis. Multisystem disease patients at diagnosis carried a 4.6-fold risk for DI compared to single system patients. Craniofacial lesions, in particular in the "ear," "eye," and oral region were associated with a significantly increased risk for DI (relative hazard rate, RHR 1.7), independent of the extent of disease. No influence of the duration of therapy could be determined, but the duration of initial disease activity (RHR 1.5) and the occurrence of reactivations (RHR 3.5) significantly increased the risk for DI.

CONCLUSIONS

Patients with multisystem disease and craniofacial involvement at diagnosis, in particular of the "ear," "eye," and the oral region carry a significantly increased risk to develop DI during their course. This risk is augmented when the disease remains active for a longer period or reactivates.

Langerhans cell histiocytosis in neonates

BACKGROUND

To study the incidence, clinical patterns, course, and outcome of neonatal Langerhans cell histiocytosis (LCH).

PROCEDURE

Retrospective analysis of the data of the Austrian/German/Swiss/Netherlands LCH Study Group. The incidence of neonatal LCH was estimated with the data from the population-based German Childhood Cancer Registry.

RESULTS

The estimated incidence of neonatal LCH (LCH diagnosed within 28 days after birth) in the population-based registry was 1-2/1,000,000. In 61/1,069 trial patients (6%), the first disease manifestations were observed in the neonatal period. However, in only 20 of them, the diagnosis was established within this period. There was a preponderance of multisystem (MS)-LCH 36/61 (59%). Cutaneous changes were the most common initial manifestation in both, single-system (SS)-LCH (92%), and MS-LCH (86%). In 72% of the MS-LCH patients, risk organs (ROs) were involved at diagnosis as well. The probability of survival at 5 years was 94% in SS-LCH and 57% in MS-LCH, which is significantly lower than in older age groups.

CONCLUSIONS

In contrast to the available literature, neonatal LCH is characterized by a clear predominance of MS-LCH. Cutaneous changes are the most common initial manifestation in neonates with both SS-LCH and MS-LCH. Prompt evaluation of disease extent upon diagnosis is mandatory for risk-adapted treatment. The disease course is unpredictable upon diagnosis. Close monitoring for disease progression is mandatory if isolated cutaneous LCH is managed by the "wait and see" approach. Neonates with MS-LCH, especially those with RO involvement at diagnosis, have less favorable prognosis compared to infants and older children, and need systemic therapy.

Improved outcome of treatment-resistant high-risk Langerhans cell histiocytosis after allogeneic stem cell transplantation with reduced-intensity conditioning

Children with multisystem Langerhans cell histiocytosis (LCH) and risk organ involvement who fail to respond to conventional chemotherapy have an extremely poor prognosis. Myeloablative stem cell transplantation (SCT) as a possible salvage approach for these patients has been associated with a high risk of transplant-related mortality. Therefore, allogeneic stem cell transplantation following a reduced-intensity conditioning regimen (RIC-SCT) has recently been performed as an alternative salvage approach. We report on the experience with allogeneic RIC-SCT in nine pediatric high-risk LCH patients. Conditioning regimen included fludarabine in all patients, melphalan in eight patients, total lymphoid irradiation in six patients, total body irradiation in two, antithymocyte globulin in five, and Campath in four patients. RIC-SCT was well tolerated with regard to common procedure-related complications. Two patients died 50 and 69 days after RIC-SCT, respectively. Seven out of the nine patients survived and showed no signs of disease activity (including one with nonengraftment and full autologous hematopoietic recovery) after median follow-up of 390 days post-SCT. Based on this observation, we conclude that RIC-SCT is a feasible procedure with low transplant-related morbidity and mortality and a promising new salvage approach for high-risk LCH patients with resistant risk organ involvement.

Modern imaging methods for the assessment of Langerhans' cell histiocytosis-associated neurodegenerative syndrome: case report

Langerhans' cell histiocytosis-associated neurodegenerative syndrome is an enigmatic manifestation, most often localized in the cerebellum and the basal ganglia. Its pathophysiologic basis is poorly understood, and effective treatment strategies are currently missing. Modern imaging modalities offer the possibility of shedding further light on this puzzling disease in a noninvasive way. We report on a 12-year-old boy with a Langerhans' cell histiocytosis-associated neurodegenerative syndrome who underwent a thorough evaluation with different modern imaging methods in addition to routine brain magnetic resonance imaging (MRI) to analyze their informative value for this condition. Additional imaging included positron emission tomography using [18F]fluorodeoxyglucose (FDG-PET), single photon emission computed tomography using [123I]2beta-carbomethoxy-3beta-(4-iodophenyl)tropane and [123I]iodobenzamide, and magnetic resonance spectroscopy. The potential relevance of each method for neurodegenerative Langerhans' cell histiocytosis is discussed based on the results obtained, and a review of the literature is made. The case underlines the fact that MRI undoubtedly possesses the major role in the diagnostic evaluation and monitoring of Langerhans' cell histiocytosis-associated neurodegenerative syndrome. FDG-PET and magnetic resonance spectroscopy findings were in good correlation with the MRI results. In particular, magnetic resonance spectroscopy could provide a valuable diagnostic tool in addition to MRI in the early detection and evaluation of the neurodegenerative component of this disease.

Neuropathology of CNS disease in Langerhans cell histiocytosis

CNS involvement in Langerhans cell histiocytosis (LCH) is a rare but potentially devastating disorder. Different types of involvement have been described by MRI. CNS changes can have space-occupying or degenerative character. Little is known about the underlying neuropathology and pathophysiology. In our study we reviewed brain samples from 12 patients with LCH. The neuropathology findings were correlated with the MR morphology and the clinical presentation. By neuropathology, three types of lesions were distinguished. (i) Circumscribed granulomas within the brain's connective tissue space corresponded to tumorous lesions in the meninges or choroid plexus on MRI. They showed a composition similar to Langerhans granulomas in peripheral organs, with variable presence of CD1a-reactive cells and pronounced CD8-positive (+) T-cell infiltration. (ii) Granulomas occur within the brain's connective tissue spaces with partial infiltration of the surrounding CNS parenchyma by CD1a-reactive histiocytes. This was associated with profound T-cell-dominated inflammation and severe neurodegeneration, characterized by a nearly complete loss of neurons and axons, and gliosis. (iii) Neurodegenerative lesions lacking infiltration of CD1a+ cells, mainly affecting the cerebellum and brainstem, exhibited a profound inflammatory process dominated by CD8-reactive lymphocytes, associated with tissue degeneration, microglial activation and gliosis. Patients with such lesions showed different stages of neurological deterioration. This study indicates that neurodegeneration in LCH occurs on the background of a T-cell-dominated inflammatory process and is characterized by neuronal and axonal destruction with secondary demyelination, resembling paraneoplastic encephalitis.

Central diabetes insipidus as presenting symptom of Langerhans cell histiocytosis

BACKGROUND AND OBJECTIVES

Central diabetes insipidus (CDI) is a rare disorder associated with various underlying diseases. Among the systemic diseases that may cause CDI, Langerhans cell histiocytosis (LCH) is the most common. Therefore, in patients with endocrinologically proven CDI, a comprehensive diagnostic evaluation is crucial to identify possible extracranial sites of LCH. The goal of the diagnostic evaluation is to yield histopathological proof of the underlying disease. If possible, this histopathological proof should be provided by a biopsy of extracranial lesions to avoid a potentially hazardous biopsy of the pituitary stalk.

STUDY DESIGN

In this retrospective study we included 54 patients registered at the LCH study reference center in whom the onset of CDI preceded the diagnosis of LCH, and we investigated their presentation and course to define a clinical pattern characteristic for LCH.

RESULTS

In 49/54 patients (91%) the detection and biopsy of extracranial lesions led to the diagnosis of LCH. The most frequently involved organs were bones, skin, and lungs; 86% of the patients with bone lesions had skull lesions. In 18% of the patients extracranial lesions were already found at presentation of CDI, in another 51% of the patients extracranial lesions were found within 1 year from onset of CDI.

CONCLUSIONS

These observations underline that a comprehensive search for extracranial lesions at presentation and during the first year thereafter may help to achieve a specific diagnosis without a pituitary stalk biopsy.

Pineal gland abnormalities in Langerhans cell histiocytosis

BACKGROUND

The most common types of central nervous system (CNS) disease in Langerhans cell histiocytosis (LCH) comprise involvement of the hypothalamic-pituitary region (HPR) and neurodegenerative changes in the cerebellum, basal ganglia or pons. In the review process of magnetic resonance images (MRI) from 129 LCH patients a high frequency of cysts within or large pineal glands was noted by chance.

PROCEDURE

To prove whether this observation was specific for LCH or not, we compared MRI findings of the HPR in LCH patients with a control group of 55 non-LCH patients with the same age and sex distribution.

RESULTS

In LCH patients, the pineal gland was significantly larger and also the number of pineal cysts was significantly higher as compared to the control group. No difference was found regarding the size or frequency of cystic changes between patients who had received chemotherapy prior to the MRI and untreated patients. In the LCH patients, we further found a significant correlation of pineal gland enlargement with involvement of the HPR, but not with neurodegenerative changes. Analysis of melatonin (the principal hormone of the pineal gland) levels in 24 hr urine in 14 LCH patients did not reveal a melatonin deficiency or overproduction in the LCH group as compared to 6 normal controls.

CONCLUSIONS

The pineal gland is another site of possible CNS involvement in LCH. LCH CNS patients did not show an overt disturbance in melatonin levels. The role of the pineal gland in CNS LCH remains to be defined.

Course and clinical impact of magnetic resonance imaging findings in diabetes insipidus associated with Langerhans cell histiocytosis

BACKGROUND

Diabetes insipidus (DI) is the most frequent sequela in Langerhans cell histiocytosis (LCH). The clinical relevance and therapeutic impact of brain magnetic resonance imaging (MRI) findings in LCH patients with LCH during the disease course is unclear.

PROCEDURE

In this retrospective study, we reviewed 113 brain MRIs from 59 DI patients, in 17 of these serial follow up MR-examination findings were correlated to the clinical course and therapy.

RESULTS

At DI diagnosis, 71% patients showed a thickened stalk, in 24% the stalk was still thickened on MRIs done more than 5 years after DI onset, and in two patients the stalk was already thickened several months before DI onset. The changes of the pituitary stalk thickness were highly variable and did not clearly correlate with the treatment. Regression of pituitary thickness on MRI did not concur with clinical recovery of DI, which persisted in all but one patient with initially partial DI. The occurrence of anterior pituitary hormone deficiencies appeared to be linked to a thickening of the stalk at DI diagnosis. LCH-lesions in the craniofacial bones were seen in 75% DI patients, and 76% of DI patients with follow up MRIs done 5 years or longer after DI diagnosis had parenchymal neurodegenerative brain changes.

CONCLUSIONS

Our study indicates that repeated MR-examinations in DI patients are of limited value for assessing a response to therapy in the pituitary stalk, but are important for the monitoring of craniofacial bone lesions and for the detection of parenchymal CNS disease.

MR imaging presentation of intracranial disease associated with Langerhans cell histiocytosis

BACKGROUND AND PURPOSE

Intracranial manifestations of Langerhans cell histiocytosis (LCH) are underestimated in frequency and diversity. We categorized the spectrum of MR imaging changes in LCH.

METHODS

We retrospectively reviewed 474 MR images in 163 patients with LCH and 55 control subjects. Lesions were characterized by anatomic region and signal intensity. Brain atrophy was assessed.

RESULTS

We noted osseous lesions in the craniofacial or skull bones in 56% of patients, meningeal lesions in 29%, and choroid-plexus involvement in 6%. In the hypothalamic-pituitary region, infundibular thickening occurred in 50%; pronounced hypothalamic mass lesions in 10%; and infundibular atrophy in 29%. The pineal gland had a cystic appearance in 28%, and pineal-gland enlargement (>10 mm) was noted in 14%. Nonspecific paranasal-sinus or mastoid opacifications were seen in 55% of patients versus 20% of controls, and accentuated Virchow-Robin spaces occurred in 70% of patients versus 27% of controls (P <.001). Intra-axial, white-matter parenchymal changes resulted in a leukoencephalopathy-like pattern in 36%. Enhancing lesions in a vascular distribution were noted in 5%. Gray-matter changes suggestive of neurodegeneration were identified in the cerebellar dentate nucleus in 40% and in the supratentorial basal ganglia in 26%. All patients with neurodegenerative lesions had lesions in the extra-axial spaces. Cerebral atrophy was found in 8%.

CONCLUSION

In LCH, cranial and intracranial changes at MR imaging include 1) lesions of the craniofacial bone and skull base with or without soft-tissue extension; 2) intracranial, extra-axial changes (hypothalamic-pituitary region, meninges, circumventricular organs); 3) intracranial, intra-axial changes (white matter and gray matter); and 4) cerebral atrophy.

Langerhans cell histiocytosis in adults. Report from the International Registry of the Histiocyte Society

Langerhans cell histiocytosis (LCH), characterised by the infiltration of one or more organs by large mononuclear cells, can develop in persons of any age. Although the features of this disease are well described in children, they remain poorly defined in adults. From January 2000 to June 2001, 274 adults from 13 countries, with biopsy-proven adult LCH, were registered with the International Histiocyte Society Registry. Information was collected about clinical presentation, family history, associated conditions, cigarette smoking and treatment, to assist in future management decisions in patients aged 18 years and older. There were slightly more males than females (143:126), and the mean ages at the onset and diagnosis of disease were 33 years (standard deviation (S.D.) 15 years) and 35 years (S.D. 14 years), respectively. 2 patients had consanguineous parents, and 1 had a family history of LCH; 129 reported smoking (47.1%); 17 (6.2%) had been diagnosed with different types of cancer. Single-system LCH, found in 86 patients (31.4%), included isolated pulmonary involvement in 44 cases; 188 patients (68.6%) had multisystem disease; 81 (29.6%) had diabetes insipidus. Initial treatment consisted of vinblastine administered with or without steroids, to 82 patients (29.9%), including 9 who had received it with etoposide, which was the sole agent given to 19 patients. 236 patients were considered evaluable for survival. At a median follow-up of 28 months from diagnosis, 15 patients (6.4%) had died (death rate, 1.5/100 person years, 95% Confidence Interval (95% CI) 0.9-2.4). The probability of survival at 5 years postdiagnosis was 92.3% (95% CI 85.6-95.9) overall, 100% for patients with single-system disease (n=37), 87.8% (95% CI 54.9-97.2) for isolated pulmonary disease (n=34), and 91.7% (95% CI 83.6-95.9) for multisystem disease (n=163). Survival did not differ significantly among patients with multisystem disease, with or without liver or lung involvement) 5-year survival 93.6% (95% CI 84.7-97.4) versus 87.5% (95% CI 65.5-95.9), respectively; P value 0.1). LCH in adults is most often a multisystem disease with the highest mortality seen in patients with isolated pulmonary involvement. It should be included in the differential diagnosis of disseminated or localised disease of the bone, skin and mucosa, as well as the lung and the endocrine and central nervous system, regardless of the age of the patient. A prospective international therapeutic study is warranted.

Response to initial treatment of multisystem Langerhans cell histiocytosis: an important prognostic indicator

BACKGROUND

Reliable prediction of prognosis allowing risk-adapted therapy remains a major issue in the management of multisystem Langerhans cell histiocytosis (LCH). In a recent publication of the International LCH Study Group, response to initial therapy appears to be a reliable outcome predictor. The aim of this study is to test this observation in a cohort of patients treated with more intensive initial therapy. Furthermore, we compare the predictive value of response to initial therapy to some other well-established stratification systems.

PROCEDURE

Response to initial combination chemotherapy (prednisolone, vinblastine, and etoposide) at 6 weeks and its prognostic value was evaluated retrospectively in 63 patients with multisystem LCH from the DAL-HX 83 and 90 Studies, and correlated to some established scoring systems from the literature.

RESULTS

After 6 weeks of therapy, 50/63 (79%) patients qualified as responders, 4/63 (7%) patients showed intermediate response, and 9/63 (14%) patients did not respond. Probability of survival at 5 years was 0.94 +/- 0.03 for responders, 0.75 +/- 0.22 for patients with intermediate response, and only 0.11 +/- 0.10 for non-responders.

CONCLUSIONS

Response to initial therapy appears to be a reliable prognostic predictor. Compared to the published international LCH-I Study, our results suggest that more intensive initial treatment allows a better discrimination between responders and non-responders. This allows to identify a subgroup of patients with extremely poor prognosis (mortality rate 90%) relatively early in the disease course.

Normal monocyte-derived dendritic cell function in patients with Langerhans-cell-histiocytosis

BACKGROUND

Langerhans cell histiocytosis (LCH) is a histiocytic disease, characterized by the lesional accumulation of dendritic Langerhans cells together with T cells and eosinophils. The cause of this disease is unknown. Langerhans cells are bone marrow-derived dendritic cells (DCs), which can develop from CD34(+) hematopoietic progenitor cells as well as from monocytes.

PROCEDURE

To test whether LCH patients have a general functional defect present in cells of their DC lineage, we generated immature DCs by culturing monocytes from nine patients with single- or multisystem LCH with GM-CSF and IL-4, and analyzed their phenotype and function before and after an in vitro maturation stimulus. Immature DCs were analyzed for their phenotype and cytokine production, DCs matured in response to TNF-alpha plus PGE(2) were analyzed for their phenotype, their stimulatory capacity in MLR, cell aggregation, and activation-induced apoptosis.

RESULTS

In summary, no difference was found between both immature as well as mature DCs generated from patients and controls regarding the expression of CD1a, CD80, CD86, MHC class I, and MCH class II antigens. Similarly, no difference was found regarding IL-10, -12, and TNF-alpha production, as well as regarding cell aggregation and apoptosis in response to external stimuli.

CONCLUSIONS

The absence of gross functional abnormalities in DCs generated from monocytes from patients with LCH makes the existence of a severe functional defect affecting all cells of the DC lineage in these patients unlikely.

Pattern and course of single-system disease in Langerhans cell histiocytosis data from the DAL-HX 83- and 90-study

BACKGROUND

Single-system (SS) disease is the most common presentation in Langerhans cell histiocytosis (LCH) with a heterogenous clinical picture and course. Mostly bone and rarely skin or lymph nodes are involved.

PROCEDURE

One hundred and seventy patients with SS-LCH were registered in the DAL-HX 83/90 studies. They were diagnosed according to uniform diagnostic criteria and followed by a standardised schedule.

RESULTS

Single bone lesions were most common (68%), followed by multiple bone lesions (19%), isolated skin disease (11%), and isolated lymph node involvement (4 patients). In the detection of bone lesions radiographic skeletal survey proved to be superior to bone scan (97% vs. 82%). Treatment comprised surgery, irradiation and local instillation of steroids, and standardised chemotherapy for multifocal bone disease. After initial therapy 81% of the patients remained disease free. Reactivations restricted to the skeleton occurred in 18% of both unifocal and multifocal bone disease. Two skin patients had a chronic course. Fatality occurred only in one infant with skin disease who progressed to multi-system disease. Twenty-five percent of all patients developed permanent consequences, which were already present at diagnosis in about half of these patients and comprised mainly orthopedic problems related to lesional sites. Diabetes insipidus occurred in 3% and anterior pituitary dysfunction in 2% of the patients.

CONCLUSIONS

The course in SS%LCH was benign. In bone disease reactivations remained restricted to the skeleton and did not influence survival. However, reactivations had an impact on morbidity, as permanent consequences were mostly related to the site of disease activity. Med Pediatr Oncol 2001;37:108-114.

A randomized trial of treatment for multisystem Langerhans' cell histiocytosis

OBJECTIVE

To compare 2 active agents, vinblastine and etoposide, in the treatment of multisystem Langerhans' cell histiocytosis (LCH) in an international randomized study.

STUDY DESIGN

One hundred forty-three untreated patients were randomly assigned to receive 24 weeks of vinblastine (6 mg/m(2), given intravenously every week) or etoposide (150 mg/m(2)/d, given intravenously for 3 days every 3 weeks), and a single initial dose of corticosteroids.

RESULTS

Vinblastine and etoposide were equivalent (P > or = .2) in all respects: response at week 6 (57% and 49%); response at the last evaluation (58% and 69%); toxicity (47% and 58%); and probability of survival (76% and 83%) [corrected], of disease reactivation (61% and 55%), and of developing permanent consequences (39% and 51%) including diabetes insipidus (22% and 23%). LCH reactivations were usually mild, as was toxicity. All children > or = 2 years old without risk organ involvement (liver, lungs, hematopoietic system, or spleen) survived. With such involvement, lack of rapid (within 6 weeks) response was identified as a new prognostic indicator, predicting a high (66%) mortality rate.

CONCLUSIONS

Vinblastine and etoposide, with one dose of corticosteroids, are equally effective treatments for multisystem LCH, but patients who do not respond within 6 weeks are at increased risk for treatment failure and may require different therapy.

Spiral CT of the lung in children with malignant extra-thoracic tumors: distribution of benign vs malignant pulmonary nodules

The purpose of this paper is to clarify the distribution of benign vs malignant pulmonary nodules which are seen on spiral CT in children with malignant extra-thoracic solid tumors. Seventy-four children with known solid, extra-thoracic tumors underwent spiral CT of the chest. According to the initial and follow-up (interval 9.2+/-4.7 months) findings, the children were graded into four groups: I = normal; II = solitary nodule unchanged at follow-up; III = multiple nodules with one or more than one unchanged at follow-up; and IV = solitary or multiple nodules all changed at follow-up. Nodules without change at follow-up were regarded as benign. Forty-nine children did present with normal pulmonary CT exams. In 7 cases solitary pulmonary nodules were found unchanged (group II) at follow-up and in 2 cases (group III) some of the nodules were stationary. Thus, 12% (9 of 74) presented with at least one pulmonary nodule that did not change at follow-up. Solitary nodules (in groups II and IV) with a diameter <5 mm were in 70 % (7 of 10) unchanged at follow-up and regarded as benign. In children with known solid extra-thoracic tumors at initial presentation, 70% of solitary nodules ( <5 mm) may be benign. To avoid overstaging, smaller solitary nodules must not automatically be regarded as metastases.

Treatment of multisystem Langerhans cell histiocytosis. Results of the DAL-HX 83 and DAL-HX 90 studies. DAL-HX Study Group

BACKGROUND

The prognosis of children with multisystem Langerhans cell histiocytosis (LCH) has improved with the application of chemotherapy. However, treatment strategies used varied from conservative approach with treatment only during disease exacerbation to intensive chemotherapy starting immediately after diagnosis. No single drug or regimen has been proven to be superior to the others. Thus, optimal treatment of multisystem LCH remains still an unsolved problem.

PATIENTS

Three hundred and twenty-four patients enrolled in the DAL-HX 83 and DAL-HX 90 studies were retrospectively re-evaluated by using the current definition for disease extent. Sixty-three patients fulfilling the criteria for multisystem LCH (involvement of > or = 2 organ systems) were object of the present study. These were 33 males and 30 females, median age at diagnosis 11.5 months (range, birth-13 years 2 months). The median observation time was 7 years 6 months (4 years-11 years 8 months).

METHODS

All patients had morphologically confirmed diagnosis, which was additionally verified through demonstration of CD1a antigen, presence of Birbeck granules or central pathologic review. Uniform evaluation including a complete medical history and physical examination, laboratory tests (complete blood count, liver function tests, coagulation profile) and radiographic survey (skeletal survey and/or radionuclide bone scan) was performed in all patients. Additional investigations (bone marrow tap, CT, MRI etc.) were performed upon specific indications. The 63 patients with multisystem LCH were evaluated with respect to response to therapy, clinical course, outcome and development of permanent disabilities. The results of the DAL-HX studies were compared with the results of the first randomized international clinical trial on multisystem LCH (LCH-I).

RESULTS

Response to 6 weeks of initial therapy showed a clear discrimination between responders and non-responders, with only 6% of the patients having intermediate response. When correlated to survival response to initial therapy appears to be a powerful prognosticator in multisystem LCH. There were some typical patterns of clinical course. Complete disease resolution at some point of the clinical course was documented in 50 (79%) patients. Thirty-five of them remained disease free, while 15 experienced one or more episodes of disease reactivation. Chronic reactivating course without complete disease resolution was observed in one patient. Deteriorating disease with fatal outcome was shown in 12 (19%) patients. The overall survival after 5 years of observation was 81%. One or more disease-related permanent disabilities were documented in 24 patients, in 4 of them these were shown at diagnosis and in 20 patients these developed after therapy had been commenced. Despite more intensive chemotherapy, the overall survival in DAL-HX 83/90 cohort was comparable with that in LCH-I studies. However, LCH-I compares unfavorably to DAL-HX 83/90 in some very important aspects. With respect to reactivation rate, reactivation free interval and development of permanent disabilities better results were achieved with the more intensive initial and prolonged continuation therapy concept of the DAL-HX studies. Even after extended analysis it remains unclear whether the superiority of the DAL-HX studies has to be attributed to the administration of continuous steroids, to the combination of vinblastine and etoposide, or to the prolonged continuation therapy including mercaptopurine. Answers to these questions are expected from the ongoing international clinical trial LCH-II.

Cyclosporine A therapy for multisystem langerhans cell histiocytosis

BACKGROUND

Treatment of multisystem Langerhans cell histiocytosis (LCH) remains difficult. Various regimens of single and multiagent chemotherapy have been used, but a significant proportion of patients fail to respond to treatment.

PROCEDURE

We have evaluated the use of cyclosporine A (CSA) in a controlled group of patients, who had received a systematic primary therapy (LCH-I). Patients received CSA either as a single agent (10 patients) or in combination with vinblastine, etoposide, prednisolone, and/or antithymocyte globulin (16 patients).

RESULTS

Among the total of 26 patients treated, a single patient developed a complete response and three a partial response, whereas 85% (22 patients) had no response to CSA.

CONCLUSIONS

CSA is at best of limited value in the treatment of patients with multisystem LCH, particularly those who had progressive disease while receiving chemotherapy.

Diabetes insipidus in Langerhans cell histiocytosis: results from the DAL-HX 83 study

Diabetes insipidus (DI) in Langerhans cell histiocytosis (LCH) is a common complication of unclear etiology. The incidence varies among different publications from 15% to 50%. In the prospective DAL-HX 83 study, 19 out of 199 patients (9.5%) registered with newly diagnosed LCH were diagnosed to have DI. All patients were stratified according to uniform criteria. One hundred and six patients with disseminated disease were treated with standardized polychemotherapy promptly after diagnosis. At the time of diagnosis of LCH, DI was already established in 8 out of 199 patients (4%). After diagnosis, DI occurred in only one out of the remaining 91 patients with localized disease (1%) and in 10 out of 100 remaining patients with disseminated disease (10%). In 8 patients, the onset of DI was associated with other signs of active LCH. The cumulative risk to develop DI after a median observation time of 5 years 3 months was 11%. Retrospective analysis of clinical features revealed multisystem involvement, skull and orbital lesions, and in particular intracranial extension from osseous lesions to constitute risk factors for DI. Magnetic resonance imaging studies (MRI) were available in 12 patients and showed abnormalities of the pituitary region in 10 children. In none of the patients with established DI was it reversed or ameliorated by any treatment. However, the rapid institution of systemic chemotherapy for disseminated disease seems to prevent the occurrence of DI and may be responsible for the low frequency of DI in the DAL-HX83 study.

Central nervous system disease in Langerhans cell histiocytosis

Diabetes insipidus and anterior pituitary dysfunction, are familiar central nervous system (CNS) complications of Langerhans cell histiocytosis (LCH) but the pathophysiology and biological behaviour of other forms of CNS involvement in LCH are poorly understood. In an attempt to improve our understanding of these rare complications, we studied 23 patients with LCH in whom neuroradiological abnormalities, with or without neurological dysfunction other than diabetes insipidus, developed during the course of disease. Neuroradiological abnormalities were of three basic types (a) poorly-defined changes in white matter, (b) well-defined changes in white and grey matter and (c) extra-parenchymal "tumoural" masses. There was a profusion of associated neurological signs and symptoms in most cases but some patients were asymptomatic. The neuropathological features were complex but infiltration of the CNS by histiocytes with xanthomatous change, particularly prominent in mass lesions, was common in the 13 cases in which biopsies were done. Patients with lytic lesions of the skull and diabetes insipidus are evidently most at risk of developing these rare manifestations of LCH. Therapeutic questions could not be answered from this study because no standard treatment had been given and outcome varied widely.

LCH-I: a randomized trial of etoposide vs. vinblastine in disseminated Langerhans cell histiocytosis. The Histiocyte Society

An international randomized trial in Langerhans cell histiocytosis (LCH) has been initiated by the Histiocyte Society. This report reviews the rationale, design, and progress of LCH-I, which compares etoposide (VP-16) and vinblastine in the treatment of disseminated LCH. Data on the risk of etoposide-associated (therapy-induced) malignancy, in the setting of histiocytosis, are reviewed. The available evidence leads to the recommendation that the study of etoposide in LCH should be continued.

Treatment strategy for disseminated Langerhans cell histiocytosis. DAL HX-83 Study Group

Treatment of Langerhans cell histiocytosis (LCH) remains problematic. To test the hypothesis that rapid initiation and long-term continuation of chemotherapy can improve survival and reduce recurrence and late consequences of disseminated LCH, we have completed a prospective clinical trial (DAL HX-83). One hundred six newly diagnosed patients were stratified into three risk groups (A: multifocal bone disease [n = 28]; B: soft tissue involvement without organ dysfunction [n = 57]; C: organ dysfunction [n = 21]). All patients received an identical initial 6-week treatment (etoposide [VP-16], prednisone, and vinblastine), and continuation treatment for 1 year, slightly adapted according to stratification at diagnosis. It included oral 6-mercaptopurine and eight pulses of vinblastine and prednisone for all patients, plus VP-16 in group B and VP-16 and methotrexate in group C. Eighty-nine percent and 91% of patients in groups A and B and 67% of the most severely affected group C, achieved complete resolution of disease. The speed of resolution was rapid (median 4 months) and independent of disease severity. The frequency of recurrence after initial resolution was low (12%, 23%, and 42% in groups A, B and C); overall fully 77% of patients have remained free of recurrence. Permanent consequences developed after diagnosis in 20% of the patients. Diabetes insipidus after initiation of treatment occurred in only 10% of patients. Mortality (9%) was limited to patients of groups B (two patients) and C (eight patients). Finally, among the 106 patients treated by DAL HX-83 none have developed a malignancy (median follow-up 6 years, 9 months). The shorter duration of active disease, low rate of recurrence and permanent consequences, and improved survival among patients with poor prognosis support the strategy of rapid initiation of a predefined prolonged treatment upon the diagnosis of disseminated LCH.

Tetrasomy 8 in acute monoblastic leukemia (AML-M5a) with myelosarcomatosis of the skin

We report a new case with isolated tetrasomy 8, an 82-year-old female patient in whom multiple disseminated nodular skin infiltrations up to 5 cm in diameter preceded acute monoblastic leukemia (AML-M5a). Despite an initial response to chemotherapy and radiotherapy, the patient died 1 year after diagnosis of relapsed leukemia. To assess the size of the tetrasomic clone, fluorescence in situ hybridization (FISH) analysis with a centromere-specific chromosome 8 probe was performed. Seventy percent of interphase cells showed four signals and 22% showed three signals. Because this trisomic clone was not detected by conventional cytogenetics, tetrasomic cells may have a proliferation advantage in vitro. Whether tetrasomy 8 arises from a simultaneous mitotic nondisjunction of both chromosomes 8 during one cell division or evolves secondarily from trisomy 8 through a second mitotic error is not known. Alternatively, trisomy 8 may originate from tetrasomy 8 by loss of one chromosome 8.

Central nervous system disease associated with Langerhans' cell histiocytosis

PURPOSE

To study the pathogenesis of central nervous system (CNS) lesions in Langerhans' cell histiocytosis (LCH), discuss their differential diagnosis and suggest guidelines for their management.

PATIENTS AND METHODS

Central nervous system (CNS) disease with Langerhans' cell histiocytosis (LCH) is a poorly understood disorder. Most commonly, the hypothalamic-pituitary region is involved, leading to diabetes insipidus (DI) or other endocrinopathies. We report four patients in whom lesions in the pons, cerebellum, basal ganglia, cerebral white matter, or optic nerve and tract were demonstrated by magnetic resonance imaging (MRI).

RESULTS

Three developed a progressive neurological disorder with cerebellar and pontine symptoms leading to severe disability--in one patient to blindness and death--in spite of various treatment approaches. In the fourth patient, who had MRI examinations to evaluate long-standing DI, CNS lesions were detected in the absence of neurological symptoms. There was no correlation between activity of LCH, severity and course of the CNS disease, or morphology of the lesions on MRI. Brain biopsy was performed in the three symptomatic patients and revealed cerebellar atrophy in one. Normal brain tissue was obtained from two patients. In none of the patients could autoantibodies to nervous system tissue be detected in serum or cerebrospinal fluid.

CONCLUSION

Based on clinical, pathological, and MRI findings in our four patients and on information in the literature, we conclude that the CNS disease associated with LCH, although insufficiently understood, is likely to be a manifestation of histiocytosis in the brain, and we propose guidelines for the management of patients with this disorder.

Conventional vs. liposomal amphotericin B in immunosuppressed children

Invasive fungal infections, mostly caused by Candida and Aspergillus species, are a major cause of early morbidity and mortality in immunocompromised children. The treatment of choice for systemic fungal infections is still the early intravenous administration of amphotericin B. However, conventional AMB therapy is often limited by severe side effects such as fever, chills, bronchospasm, and nephrotoxicity. In recent reports liposomal AMB (AmBisome) was shown to be effective in the treatment of severe systemic fungal infections. So far, clinical experience with AmBisome in children is still anecdotal and no comparative study is yet available. In the following we report on 11 immunosuppressed children who were treated with conventional or liposomal AMB for longer than 3 weeks.

Hepatic and splenic abscesses--a common complication of intensive chemotherapy of acute myeloid leukemia (AML). A prospective study

In order to determine the frequency of hepatosplenic abscesses in AML patients during chemotherapy and to evaluate the clinical and laboratory characteristics of this complication we performed a prospective study over a 28-month period. Fifty-five consecutive patients with de novo AML or relapse who received intensive chemotherapy underwent regular ultrasound examinations. In 16 patients (29.1%) hepatic and/or splenic abscesses were detected sonographically. Histopathological evidence for abscess formation was obtained in five of these 16 patients. In three patients granulation tissue and in one patient necrotizing granulomas were found. Causative micro-organisms were proven in only three patients: Candida hyphae were demonstrated in one patient, gram-positive cocci in another. Bacteria and fungi were seen in the tissue specimen of the third patient. Patients with hepatosplenic abscesses had significantly prolonged fever after neutrophil recovery but did not differ from patients without abscesses in any other laboratory or clinical features. Due to the absence of specific alerting clinical and laboratory signs and symptoms of hepatosplenic abscesses, routine ultrasound examination is required for detection of this complication. The presence of hepatic and/or splenic abscesses does not necessarily worsen the prognosis, but it may influence the decision on further chemotherapy and antimicrobial treatment.

Trisomy 4: a specific karyotype anomaly in primary and secondary acute myeloid leukemia

Trisomy 4 as single karyotype anomaly has recently been proposed as an acute myeloid leukemia (AML) specific aberration. Up to now, 20 cases have been reported in which the single abnormality occurred without additional chromosomal aberrations. Trisomy 4 has been found in both primary and secondary AML, the majority of cases being diagnosed as FAB M4 or M2 subtypes. In the cytogenetic analysis of 305 patients with AML, we found 209 cases with aberrant karyotypes, among them two patients (22a, male, M2; and 69a, male, M4) with trisomy 4 as single aberration. The younger patient achieved complete remission lasting 13 months and survived 22 months whereas the older patient died in aplastic phase due to septicaemia 5 weeks after admission. Trisomy 4 is proposed to be the primary aberration in both these cases of de novo AML. Although in one case, as in two cases reported earlier, cytogenetic results were only available in first relapse, we have no indication that trisomy 4 appeared in a secondary induced leukemia, because the leukemic blasts of the relapse were morphologically identical to first acute phase. In contrast to other specific chromosomal aberrations, results indicate that trisomy 4 has as yet no prognostic relevance concerning the clinical outcome.

1-Deamino-8-D-arginine vasopressin in the treatment of non-haemophilic patients with acquired factor VIII inhibitor

1-Deamino-8-D-arginine vasopressin (DDAVP) was administered to 3 patients with spontaneous factor VIII inhibitors. In 2 patients with baseline factor VIII levels above 1%, a marked increase of factor VIII activity after DDAVP infusion could be observed. No rise of factor VIII activity after DDAVP was seen in the 3rd patient with a baseline factor VIII level of less than 1%. Daily infusion of DDAVP resulted in a reduction of the efficacy, but the full effect could be retained when DDAVP was given at 48-hour intervals. The effect of DDAVP infusion on factor VIII levels in the 2 responding patients was superior to the treatment with 30 U/kg factor VIII concentrate and approximately equivalent to infusion of 45 U/kg factor VIII concentrate. DDAVP may be a useful and less expensive treatment for patients with acquired factor VIII inhibitors and a baseline factor VIII level of more than 1%.

[Hepatic and splenic abscesses in immunosuppressed patients]

Morphologic characteristics of hepatosplenic abscesses using ultrasound and CT examinations in 13 immunosuppressed patients are presented. Additionally, the results of diagnostic ultrasound and CT guided biopsy procedures (n = 13) are reported. On sonograms, bacterial abscesses were exclusively hypoechoic lesions whereas patients with mycotic abscesses showed additionally target lesions and lesions presenting a "wheels-within-wheels" appearance. Thus, with some limitations, us might help to differentiate between fungal and bacterial abscesses. On CT, all patients presented uniformly with hypodense lesions. Follow-up ultrasound studies showed these abscesses over periods as long as 24 months; biopsy proved some of these as fibrotic lesions without vital bacteria or fungi.

Is trisomy 22 in acute myeloid leukemia a primary abnormality or only a secondary change associated with inversion 16?

In an attempt to confirm the existence of acute myeloid leukemia (AML) with trisomy 22, we studied three patients in whom trisomy 22 imposed as the sole karyotype abnormality. After revision of the karyotypes, however, we were able to identify an inv(16) as the important primary abnormality in all of them. Based on this experience, we investigated whether at least some of the 17 AML cases with trisomy 22 reported so far might possibly have been misinterpreted. Interestingly, ten out of 16 evaluable cases were classified as M4, some of them with bone marrow eosinophilia. As in cases with inv(16), only few metaphases contained trisomy 22. Furthermore, in at least two out of the only four published karyotypes of cases with trisomy 22, an inv(16) is evident and in the other two cases it cannot be ruled out. We therefore believe that at least some of the trisomy 22 cases mentioned in the literature are in fact only secondary changes occurring in AML with an inv(16) and suggest that future reports of AML with trisomy 22 as a specific primary abnormality can only be accepted as such if inv(16) has been excluded with appropriate methods.