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E. Van Mieghem,
A. Wozniak,
Y. Geussens,
J. Menten,
S. De Vleeschouwer,
F. Van Calenbergh, R. Sciot,
S. Van Gool,
O. E. Bechter,
P. Demaerel,
G. Wilms,
P. M. Clement
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ABSTRACT: BACKGROUND AND PURPOSE: Pseudoprogression is a frequent phenomenon observed since the introduction of postoperative therapy with radiotherapy and temozolomide (RT/TMZ) in glioblastoma multiforme (GBM) patients. However, the criteria defining pseudoprogression, its incidence, the time of occurrence and its impact on therapy and outcome remain poorly defined. METHODS: The objective of this study is to compare two sets of criteria (liberal and stringent), defining pseudoprogression, in a cohort of patients treated before and after the introduction of RT/TMZ in the standard postoperative treatment. This retrospective review includes 136 unselected and consecutively treated patients with pathologically diagnosed GBM. RESULTS: Pseudoprogression was observed in 10 (12%) cases applying the stringent criteria, and in 18 (23%) patients when using the liberal criteria, in the cohort treated with RT/TMZ. Pseudoprogression was observed in only one patient treated with RT alone. The median time to pseudoprogression was 4 weeks after the end of RT. Patients with pseudoprogression had a median survival time of 28 months, compared with 12 months for patients without pseudoprogression. CONCLUSIONS: The incidence of pseudoprogression after RT/TMZ strongly depends on the applied criteria. However, regardless of the stringency of the criteria, the impact on survival remains the same.
Eur J Neurol. 01/2013;
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ABSTRACT: Reports of coexisting osteonecrosis of more than one carpal bone are rare. We report an osteonecrosis of the entire proximal carpal row of the wrist, started briefly after intravenous bisphosphonate administration. The use of bisphosphonates for the treatment of osteoporosis is increasing. Osteonecrosis of the jaw (ONJ) is one of the known adverse effects during chronic treatment with bisphosphonates. This case is reported to make clinicians aware of a possible causative link between bisphosphonate use and osteonecrosis of other bones.
Chirurgie de la Main 10/2012; · 0.53 Impact Factor
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ABSTRACT: Vorgestellt werden zwei Fälle primärer atypischer lipomatöser Tumoren (ALT) des Magens. Im 1.Fall wurde bei einer 60-jährigen
Patientin ein 7×4×3cm großer submuköser ALT (lipomähnlicher Subtyp) der Antrum-/Pylorusregion komplett reseziert. Mit Hilfe
der Interphasen-dual-color-FISH waren MDM2- und CDK4-Amplifikationen in unterschiedlichen Amplicons nachweisbar. Es ergab sich ein kontinuierliches krankheitsfreies Überleben
bei 56Monaten Follow-up. Im 2.Fall wurde bei einer 56-jährigen Patientin ein 3,5cm im Durchmesser großer submuköser ALT
(lipomähnlicher Subtyp) im Korpusbereich hinterwandseitig vollständig reseziert. In der FISH war eine Amplifikation von MDM2 bei fehlender Genamplifikation von CDK4 zu belegen. Nach einem Follow-up von 36Monaten lag ein kontinuierlich krankheitsfreies Überleben vor. Die morphologischen
und molekularbiologischen Befunde dieses seltenen primären mesenchymalen Tumors des Magens werden im Vergleich zu den entsprechenden
Tumoren des Weichgewebes diskutiert.
Two cases of primary gastric atypical lipomatous tumors (ALT) are presented. In case No.1, a 7×4×3cm submucosal ALT (lipoma-like
subtype) of the antrum/pyloric region in a 60-year-old woman was completely resected. Using interphase dual-color-FISH, MDM2- and CDK4 amplifications could be detected in distinguished amplicons. The patient was continuously free of disease after 56months.
In case No. 2, a 3.5cm (in diameter) submucosal ALT (lipoma-like subtype) of the gastric body in a 56-year-old woman was
completely resected. FISH revealed MDM2 amplification while the CDK4 gene remained in diploid copies. This patient was continuously free of disease after 36months. The morphologic and molecular
biological findings of this rare primary gastric mesenchymal tumor are discussed in comparison with the corresponding soft
tissue lesions.
SchlüsselwörterMagen-Atypischer lipomatöser Tumor-Liposarkom-FISH-
MDM2
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CDK4
KeywordsStomach-Atypical lipomatous tumor-Liposarcoma-FISH-
MDM2
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CDK4
Der Pathologe 04/2012; 31(3):199-204. · 0.67 Impact Factor
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ABSTRACT: Der Fall eines lipomatösen Tumors mit prädominierender Lipomkomponente und Übergang zu einem atypischen lipomatösen Tumor
(ALT) vom lipomähnlichen Typ wird vorgestellt. Bei einer 70-jährigen Patientin wurde am rechten Oberschenkel ein tief lokalisierter
Weichgewebstumor mit einer maximalen Größe bis 14cm reseziert. Korrespondierend zum makroskopischen Erscheinungsbild bot
der Tumor überwiegend das histologische Bild eines Lipoms ohne Atypie. Im restlichen Anteil (etwa 20%) fanden sich histologische
Befunde eines ALT vom lipomähnlichen Typ. Immunhistochemisch war keine MDM2-/CDK4-Expression innerhalb der Lipomkomponente,
jedoch in der ALT-Komponente zu belegen. Mit Hilfe der Fluoreszenz-in-situ-Hybridisierung war keine MDM2-Gen-Amplifikation und nur vereinzelt eine CDK4-Amplifikation innerhalb des Lipomanteils, jedoch eine deutliche Amplifikation des MDM2-/CDK4-Gens in der ALT-Komponente nachweisbar, wodurch die morphologisch basierte Diagnose eines lipomatösen Tumors mit Arealen
eines Lipoms und eines atypischen lipomatösen Tumors innerhalb einer Neoplasie zusätzlich molekularbiologisch belegt wurde.
Der hier dargestellte Fall spricht für den graduellen Übergang eines Lipoms zu einem ALT und untermauert das Konzept einer
kontinuierlichen schrittweisen Entwicklung benigner zu malignen lipomatösen Weichgewebstumoren im Sinne eines biologischen
Kontinuums.
The case of a lipomatous tumor with a predominant lipoma component and transition to an atypical lipomatous tumor is presented.
A deep-seated soft tissue tumor of the right thigh with a maximum size of 14cm was resected in a 70-year-old female patient.
Corresponding to a comparable macroscopic aspect, the lesion revealed the histological features of an ordinary lipoma without
atypia in about 80% of the specimen. In the remaining portion (approximately 20%) histopathology showed an atypical lipomatous
tumor (ALT, lipoma-like subtype). Immunohistochemistry for MDM2 and CDK4 revealed no immunoreactivity in the lipoma component,
but within the ALT component. Interphase dual-color fluorescence in situ hybridization showed no amplification of the MDM2 gene and rarely CDK4 gene amplification within the lipoma component, but high level amplification of MDM2/CDK4 gene in the ALT area, further supporting the morphologically based diagnosis of a lipomatous tumor including areas of a true
lipoma and ALT. This case underlines the concept of a continuous stepwise development of lipomatous soft tissue tumors from
benign to malignant counterparts as a biological continuum.
SchlüsselwörterLipom-Atypischer lipomatöser Tumor-Liposarkom-Fluoreszenz-in-situ-Hybridisierung
KeywordsLipoma-Atypical lipomatous tumor-Liposarcoma-Fluorescence in situ hybridization
Der Pathologe 04/2012; 31(2):129-134. · 0.67 Impact Factor
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C Mackintosh,
J L Ordóñez,
D J García-Domínguez,
V Sevillano,
A Llombart-Bosch,
K Szuhai,
K Scotlandi,
M Alberghini, R Sciot,
F Sinnaeve,
P C W Hogendoorn,
P Picci,
S Knuutila,
U Dirksen,
M Debiec-Rychter,
K-L Schaefer,
E de Álava
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ABSTRACT: Despite extensive characterization of the role of the EWS-ETS fusions, little is known about secondary genetic alterations and their clinical contribution to Ewing sarcoma (ES). It has been demonstrated that the molecular structure of EWS-ETS lacks prognostic value. Moreover, CDKN2A deletion and TP53 mutation, despite carrying a poor prognosis, are infrequent. In this scenario identifying secondary genetic alterations with a significant prevalence could contribute to understand the molecular mechanisms underlying the most aggressive forms of ES.We screened a 67 ES tumor set for copy number alterations by array comparative genomic hybridization. 1q gain (1qG), detected in 31% of tumor samples, was found markedly associated with relapse and poor overall and disease-free survival and demonstrated a prognostic value independent of classical clinical parameters. Reanalysis of an expression dataset belonging to an independent tumor set (n=37) not only validated this finding but also led us to identify a transcriptomic profile of severe cell cycle deregulation in 1qG ES tumors. Consistently, a higher proliferation rate was detected in this tumor subset by Ki-67 immunohistochemistry. CDT2, a 1q-located candidate gene encoding a protein involved in ubiquitin ligase activity and significantly overexpressed in 1qG ES tumors, was validated in vitro and in vivo proving its major contribution to this molecular and clinical phenotype. This integrative genomic study of 105 ES tumors in overall renders the potential value of 1qG and CDT2 overexpression as prognostic biomarkers and also affords a rationale for the application of already available new therapeutic compounds selectively targeting the protein-ubiquitin machinery.
Oncogene 08/2011; 31(10):1287-98. · 6.37 Impact Factor
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ABSTRACT: A 36-year-old woman presented with a feeling of pressure in the right orbit and proptosis of the right eye after a "common cold".
Computed tomography (CT) of the maxillofacial region revealed, and endoscopy confirmed, a mass in the right ethmoid sinus, eroding the lamina papyracea and extending into the orbit. Pathology of multiple biopsies revealed a nasal neoplasm composed of neuroectodermal and mesenchymal neoplastic elements, suggestive of a malignant ectomesenchymoma (MEM). Magnetic resonance imaging was used for MEM staging. Computed tomography of the chest and abdomen show no evidence of distant metastases.
Due to the intracranial and intraorbital extension of the tumour, radical surgery was not an option. Appropriate chemotherapy (6 cycles of vincristine/ifosfamide/adriamycin and 2 cycles of vincristine/ifosfamide/cisplatin) and intensity-modulated radiation therapy were administered.
Twenty-eight months after treatment, there was no evidence of residual or metastatic disease.
B-ENT 01/2011; 7(3):201-4.
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[show abstract]
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ABSTRACT: Two cases of primary gastric atypical lipomatous tumors (ALT) are presented. In case No.1, a 7x4x3 cm submucosal ALT (lipoma-like subtype) of the antrum/pyloric region in a 60-year-old woman was completely resected. Using interphase dual-color-FISH, MDM2- and CDK4 amplifications could be detected in distinguished amplicons. The patient was continuously free of disease after 56 months. In case No. 2, a 3.5 cm (in diameter) submucosal ALT (lipoma-like subtype) of the gastric body in a 56-year-old woman was completely resected. FISH revealed MDM2 amplification while the CDK4 gene remained in diploid copies. This patient was continuously free of disease after 36 months. The morphologic and molecular biological findings of this rare primary gastric mesenchymal tumor are discussed in comparison with the corresponding soft tissue lesions.
Der Pathologe 03/2010; 31(3):199-204. · 0.67 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: The case of a lipomatous tumor with a predominant lipoma component and transition to an atypical lipomatous tumor is presented. A deep-seated soft tissue tumor of the right thigh with a maximum size of 14 cm was resected in a 70-year-old female patient. Corresponding to a comparable macroscopic aspect, the lesion revealed the histological features of an ordinary lipoma without atypia in about 80% of the specimen. In the remaining portion (approximately 20%) histopathology showed an atypical lipomatous tumor (ALT, lipoma-like subtype). Immunohistochemistry for MDM 2 and CDK4 revealed no immunoreactivity in the lipoma component, but within the ALT component. Interphase dual-color fluorescence in situ hybridization showed no amplification of the MDM 2 gene and rarely CDK4 gene amplification within the lipoma component, but high level amplification of MDM 2/CDK4 gene in the ALT area, further supporting the morphologically based diagnosis of a lipomatous tumor including areas of a true lipoma and ALT. This case underlines the concept of a continuous stepwise development of lipomatous soft tissue tumors from benign to malignant counterparts as a biological continuum.
Der Pathologe 03/2010; 31(2):129-34. · 0.67 Impact Factor
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J Dômont,
S Salas,
L Lacroix,
V Brouste,
P Saulnier,
P Terrier,
D Ranchère,
A Neuville,
A Leroux,
L Guillou, R Sciot,
F Collin,
A Dufresne,
J-Y Blay,
A Le Cesne,
J-M Coindre,
S Bonvalot,
J Bénard
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ABSTRACT: Fibromatosis comprises distinct clinical entities, including sporadic extra-abdominal fibromatosis, which have a high tendency for recurrence, even after adequate resection. There are no known molecular biomarkers of local recurrence. We searched for beta-catenin mutations in a European multicentre series of fibromatosis tumours to relate beta-catenin mutational status to disease outcome.
Direct sequencing of exon 3 beta-catenin gene was performed for 155 frozen fibromatosis tissues from all topographies. Correlation of outcome with mutation rate and type was performed on the extra-abdominal fibromatosis group (101 patients).
Mutations of beta-catenin were detected in 83% of all cases. Among 101 extra-abdominal fibromatosis, similar mutation rates (87%) were observed, namely T41A (39.5%), S45P (9%), S45F (36.5%), and deletion (2%). None of the clinico-pathological parameters were found to be significantly associated with beta-catenin mutational status. With a median follow-up of 62 months, 51 patients relapsed. Five-year recurrence-free survival was significantly worse in beta-catenin-mutated tumours regardless of a specific genotype, compared with wild-type tumours (49 vs 75%, respectively, P=0.02).
A high frequency (87%) of beta-catenin mutation hallmarks extra-abdominal fibromatosis from a large multicentric retrospective study. Moreover, wild-type beta-catenin seems to be an interesting prognostic marker that might be useful in the therapeutic management of extra-abdominal fibromatosis.
British Journal of Cancer 03/2010; 102(6):1032-6. · 5.04 Impact Factor
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ABSTRACT: Cytogenetic analysis was performed of six monophasic synovial sarcomas (four primary, two recurrent tumors) and one recurrent poorly differentiated synovial sarcoma with complex tumor-specific t(X;18). In the complex translocations, besides chromosomes X and 18, the following chromosomes were involved: 1, 3, 5, 15, and 17. In all, taking these results together with findings of 20 previously published synovial sarcoma tumors with complex t(X;18), 13 different chromosomes were involved. Chromosomes 15 (22% of tumors) and 1, 5, and 12 (approximately 11% each) were the most frequently involved in complex translocation, but with different breakpoints. In our laboratories, complex tumor-specific t(X;18) ranged from 2.5% to 11.7% (average 6.5%) of synovial sarcoma karyotypes.
Cancer genetics and cytogenetics 04/2009; 189(2):118-21. · 1.54 Impact Factor
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ABSTRACT: Myxoid tumours of soft tissue are characterized by their so-called 'myxoid' extracellular matrix. The aim was to investigate the composition and possible function of this matrix which is poorly understood.
Using Alcian Blue staining with and without pretreatment with hyaluronidase and application of the critical electrolyte concentration method followed by densitometry, the glycosaminoglycan composition of three different myxoid tumours was studied. The composition of glycosaminoglycans varied with tumour type and grade, despite their general characterization as myxoid tumours. Intramuscular myxoma contained similar amounts of the various glycosaminoglycans as grade I myxofibrosarcoma; grade III myxofibrosarcoma contained less hyaluronic acid and more heparan sulphate, whereas extraskeletal myxoid chondrosarcoma contained predominantly chondroitin-4 and -6 sulphates. Western blot identified albumin as a major protein in tumour lysates, and its presence in the extracellular matrix and cytoplasm of the majority of tumours was demonstrated by immunohistochemistry; production of albumin by the tumour cells was confirmed by quantitative polymerase chain reaction.
The extracellular matrix of myxoid tumours of soft tissue has a heterogeneous composition consisting of, amongst others, glycosaminoglycans and albumin, which appear to play an active role in their morphogenesis.
Histopathology 04/2008; 52(4):465-74. · 3.08 Impact Factor
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ABSTRACT: Lipoblastoma is a rare benign adipocytic neoplasm that occurs primarily in infancy and early childhood. Histologically, there is some morphological overlap with atypical lipomatous tumour and myxoid liposarcoma and the age at presentation is often regarded as a major diagnostic criterion. However, we recently encountered several cases of lipoblastoma occurring in adolescents and young adults. The aim was to document the occurrence of lipoblastoma in older patients, with cytogenetic confirmation.
Six cases of lipoblastoma in patients >12 years old were identified. The tumours occurred in four male and two female patients ranging from 14 to 24 years old. Our cases showed the classical histological features of lipoblastoma. Three tumours were composed predominantly of mature adipocytes and the three other cases showed an immature appearance, with a prominent myxoid matrix. Fluorescence in situ hybridization (FISH) demonstrated rearrangements of the PLAG1 region in two cases and polysomy for chromosome 8 in three other cases. None of the tumours had amplification of MDM2 or CDK4.
Lipoblastoma occurs rarely in young adults and should enter into the differential diagnosis of 'atypical' fatty tumours in adults. Our report underscores the diagnostic value of FISH analysis.
Histopathology 02/2008; 52(3):294-8. · 3.08 Impact Factor
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ABSTRACT: Epstein-Barr virus (EBV) has been implicated in the pathogenesis of different types of malignancies. While nonmelanoma skin cancers, lymphomas and Kaposi sarcomas are the most frequently reported malignancies after solid organ transplantation, EBV-associated smooth muscle tumors (EBV-SMT) after transplantation are rare and thus far only 18 cases in kidney recipients have been reported. A case of a 51-year-old kidney transplant recipient diagnosed with EBV-SMT is reported together with a review of the literature.
American Journal of Transplantation 02/2008; 8(1):253-8. · 6.39 Impact Factor
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ABSTRACT: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder that results in the selective loss of motor neurones. In the present study, the involvement of the antiapoptotic protein, Akt (protein kinase B), was studied. We found that motor neurones of both sporadic and familial ALS patients lack phospho-Akt, and that motor neurones of mutant SOD1 mice lose activated Akt early in the disease, before the onset of clinical symptoms. In vitro, overexpression of constitutively active Akt protects against mutant SOD1-dependent cell death. In vivo, levels of phospho-Akt in the spinal cord increase after intracerebroventricular administration of vascular endothelial growth factor to mutant SOD1 rats, a treatment we previously described to significantly protect motor neurones. From these results, we conclude that the loss of phospho-Akt could be involved in motor neurone death in ALS, and that therapies upregulating phospho-Akt thus might be of clinical relevance.
Neuropathology and Applied Neurobiology 11/2007; 33(5):499-509. · 3.80 Impact Factor
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ABSTRACT: A case of a histologically proven rhabdoid tumor of the cervical spine in a 19-year-old Caucasian male is presented. Primary extrarenal rhabdoid tumors are very rare. When the central nervous system is involved, the tumor usually is located in the brain. Only three cases of primary spinal rhabdoid tumor have been reported. This case is the first reported extradural rhabdoid tumor of the spinal canal and the first case of a rhabdoid tumor located in the spinal canal with bony involvement.
Skeletal Radiology 05/2007; 36(4):341-5. · 1.54 Impact Factor
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K Cromphout,
W Vleugels,
L Heykants,
E Schollen,
L Keldermans, R Sciot,
R D'Hooge,
P P De Deyn,
K von Figura,
D Hartmann,
C Körner,
G Matthijs
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ABSTRACT: Phosphomannomutases (PMMs) are crucial for the glycosylation of glycoproteins. In humans, two highly conserved PMMs exist: PMM1 and PMM2. In vitro both enzymes are able to convert mannose-6-phosphate (mannose-6-P) into mannose-1-P, the key starting compound for glycan biosynthesis. However, only mutations causing a deficiency in PMM2 cause hypoglycosylation, leading to the most frequent type of the congenital disorders of glycosylation (CDG): CDG-Ia. PMM1 is as yet not associated with any disease, and its physiological role has remained unclear. We generated a mouse deficient in Pmm1 activity and documented the expression pattern of murine Pmm1 to unravel its biological role. The expression pattern suggested an involvement of Pmm1 in (neural) development and endocrine regulation. Surprisingly, Pmm1 knockout mice were viable, developed normally, and did not reveal any obvious phenotypic alteration up to adulthood. The macroscopic and microscopic anatomy of all major organs, as well as animal behavior, appeared to be normal. Likewise, lectin histochemistry did not demonstrate an altered glycosylation pattern in tissues. It is especially striking that Pmm1, despite an almost complete overlap of its expression with Pmm2, e.g., in the developing brain, is apparently unable to compensate for deficient Pmm2 activity in CDG-Ia patients. Together, these data point to a (developmental) function independent of mannose-1-P synthesis, whereby the normal knockout phenotype, despite the stringent conservation in phylogeny, could be explained by a critical function under as-yet-unidentified challenge conditions.
Molecular and Cellular Biology 09/2006; 26(15):5621-35. · 5.53 Impact Factor
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Histopathology 04/2006; 48(4):473-5. · 3.08 Impact Factor
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G Huygh,
Paul M J Clement,
H Dumez,
P Schöffski,
H Wildiers,
J Selleslach,
J M Jimeno,
I De Wever, R Sciot,
L Duck,
A T Van Oosterom
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ABSTRACT: Purpose. To evaluate the activity and safety of ecteinascidin (ET-743) in pretreated patients with advanced or metastatic soft tissue and bone sarcoma. Patients or subjects. Eighty-nine patients received ET-743 as a 24-hour continuous infusion at a dose of 900-1500 mug/m(2) every 3 weeks. Results. We observed one complete remission, 5 partial remissions, one minimal response, and 16 patients with a disease stabilization of 6 months or more. The objective response rate was 6.7% and the clinical benefit rate at 3 and 6 months was 37.7% and 23.4%, respectively. Responses were noted in patients with lipo-, leiomyo-, osteo-, and myogenic sarcoma, with a median duration of 9.85 months. Toxicity mainly involved an asymptomatic elevation of transaminases and neutropenia. Estimated 1- and 2-year survival rates were 39.4% and 15.8%. Median overall survival was 8.25 months. Discussion. This retrospective analysis confirms that ET-743 induces objective responses and progression arrest in a clinically relevant proportion of patients.
Sarcoma 02/2006; 2006:56282.
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K Cromphout,
L Keldermans,
A Snellinx,
J F Collet,
S Grünewald,
N De Geest, R Sciot,
E Vanschaftingen,
J Jaeken,
G Matthijs,
D Hartmann
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[hide abstract]
ABSTRACT: The most common type of the congenital disorders of glycosylation, CDG-Ia, is caused by mutations in the human PMM2 gene, reducing phosphomannomutase (PMM) activity. The PMM2 mutations mainly lead to neurological symptoms, while other tissues are only variably affected. Another phosphomannomutase, PMM1, is present at high levels in the brain. This raises the question why PMM1 does not compensate for the reduced PMM2 activity during CDG-Ia pathogenesis. We compared the expression profile of the murine Pmm1 and Pmm2 mRNA and protein in prenatal and postnatal mouse brain at the histological level. We observed a considerable expression of both Pmms in different regions of the embryonic and adult mouse brain. Surprisingly, the expression patterns were largely overlapping. This data indicates that expression differences on the cellular and tissue level are an unlikely explanation for the absence of functional compensation. These results suggest that Pmm1 in vivo does not exert the phosphomannomutase-like activity seen in biochemical assays, but either acts on as yet unidentified specific substrates or fulfils entirely different functions.
European Journal of Neuroscience 09/2005; 22(4):991-6. · 3.63 Impact Factor
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ABSTRACT: The diagnosis of gastrointesinal stromal tumours (GISTs) is widely based on morphological features and KIT (CD117) immunoreactivity. Most patients with advanced GISTs show a major clinical response after treatment with imatinib mesylate. The histopathological features of GISTs in patients on prolonged imatinib treatment have, thus far, not been addressed in detail. In this report, we present three patients with metastatic GISTs, who received more than 1 year of therapy with imatinib, and whose tumours changed their morphological and immunohistochemical characteristics during continued treatment with the drug.
All three primary GISTs from these patients were classical spindle-type tumours, showing diffuse, strong CD117, CD34, and focal alpha-smooth muscle actin expression. During treatment, two clinically progressive and one clinically stable GIST revealed a diffuse epithelioid, or pseudopapillary epithelioid growth pattern, characterized by rounded cells with eosinophilic cytoplasm and uniform round-to-ovoid nuclei. In addition, GIST specimens from patients on therapy showed complete loss of CD117 immunoreactivity. Remarkably, two of these tumours also became CD34 immunonegative and in one case the progression was accompanied by desmin expression. KIT mutational analysis revealed the presence of distinct exon 11 mutant isoforms in all cases examined, while the same genotype was sustained in the base line and on-therapy tumour specimens, proving the common origin of analysed specimens.
GISTs subject to imatinib treatment can undergo striking (immuno)phenotypic changes, which are not necessarily corroborated by new genotypic modifications. Because these may mimic other tumour types, this feature creates a differential diagnostic challenge, of which the pathologist should be aware.
Histopathology 08/2005; 47(1):41-7. · 3.08 Impact Factor
