The role of cytogenetics in the classification of soft tissue tumours

 Soft tissue tumours represent a heterogeneous group of mesenchymal lesions, and their classification is the subject of continuous debate. Chromosome analysis, molecular cytogenetics and molecular assays may become increasingly useful in diagnosis, and this review summarises advances in the cytogenetic characterisation and classification of soft tissue tumours. Among the group of fibrous lesions, superficial fibromatosis exhibits trisomy 8. This genomic change is also observed in desmoid fibromatosis in association with trisomy 20. Trisomy 11 is the most frequently observed chromosomal aberration in congenital fibrosarcoma. Dermatofibrosarcoma protuberans and giant cell fibroblastoma share a translocation t(17;22), which supports the concept of the existence of a common differentiation pathway. Adipose tissue tumours is the group in which integration of genetics and pathology has been most fruitful. Ordinary lipomas cytogenetically show an abnormal karyotype in about half the cases. Genomic changes of the 11q13 region are observed in hibernoma. Lipoblastoma exhibits a specific 8q rearrangement in 8q11-q13. Loss of material from the region 16q13-qter and 13q deletions are observed in spindle cell/pleomorphic lipomas. The well-differentiated liposarcoma/atypical lipoma group is characterised karyotypically by the presence of one extra ring and/or extra giant chromosome marker. Myxoid and round cell liposarcoma share the same characteristic chromosome change: t(12;16)(q13;p11) in most cases. In the group of smooth muscle lesions most data are derived from uterine leiomyomas, which can be subclassified cytogenetically into seven different types. Half of all leiomyomas are chromosomally normal; the other half have one of six possible consistent chromosome changes. Alveolar rhabdomyosarcoma is characterised cytogenetically by two variant translocations t(2;13)(q35;q14) and t(1;13)(p36;q14). Among tenosynovial tumours, the localised type of giant cell tumour of tendon sheath exhibits two different karyotypic changes. One involves 1p11 in a translocation with chromosome 2 or with another chromosome. A second type involves 16q24. Synovial sarcoma is characterised cytogenetically by a translocation occurring between chromosome 18 and presumably two adjacent loci on the X chromosome. In neural tumours, abnormalities of chromosome 22 have been reported in benign schwannomas and perineuriomas. Malignant peripheral nerve sheath tumours exist in two main forms: sporadic and associated with the NF-1 syndrome. Karyotypes are very complex, but chromosomes 17q and 22q are very often involved. Clear cell sarcoma is characterised cytogenetically and molecularly by a translocation t(12;22)(q13;q12). The Ewing’s sarcoma/peripheral neuroectodermal tumour category shows a central karyotypic anomaly represented by the translocation t(11;22). The two variants t(21;22) and t(7;22) are found in some cases. Among cartilaginous lesion, the most frequently described anomaly is the t(9;22)(q22;q12) in extraskeletal myxoid chondrosarcoma. Intra-abdominal desmoplastic small round cell tumour is characterised by a t(11;22)(p13;q12). Received: 5 February 1997 / Accepted: 24 February 1997     

False-Positive Computed Tomographic Findings in a Series of 525 Patients with Acoustic Neuromas

In our series of 525 patients operated on for acoustic neuroma, there were three false-positive computed tomography findings resulting in unnecessary surgery. The histories and results of laboratory investigations and surgery are presented. Discussion of the outcome had gadolinium-enhanced magnetic resonance imaging been performed is presented.     

Long-term result of guided nerve regeneration with an inert microporous polytetrafluoroethylene conduit

Thedevelopmentinmicrosurgicaltechniqueshasgreatlyimprovednervefunctionalrecovery .However ,owingtotheinabilitytocoaptateandsuturethousandsofnervefiberstotheirfunctionallysimilarnervefibersandinaccuratesutureofthenervestumps ,regeneratednervefiberspartiallylosethechancetoselectivelyregrowintotheirtargetendoneurialtubes,1 4whichresultsinaninevitablemismatchofmotorandsensorynervefibers .Thus,thecontact guidance basedmicrosurgicalnerverepairhasfailedtoachieveconsistentsatisfactoryfunctionalrecover…     

A morphometric study of the reversal of ACTH-induced hypertrophy of rat adrenocortical cells after cessation of treatment

The effect of a prolonged (7-day) ACTH administration on rat zona fasciculata cells and its reversal after cessation of treatment was investigated by morphometry. ACTH treatment caused a notable cell hypertrophy, which was mainly due to the increase in the volume of the mitochondrial compartment and to smooth endoplasmic reticulum (SER) proliferation, and a conspicuous rise in the basal level of corticosterone. After cessation of ACTH administration, rat zona fasciculata cells underwent a time-dependent atrophy, so that after 5 days they resembled those of control animals, and the blood concentration of corticosterone reverted to the base-line value. The cell atrophy was provoked by the decrease in the volumes of the mitochondrial compartment and SER, and was associated with a striking time-dependent accumulation of dense bodies. Stereology demonstrated that during the first two days after ACTH withdrawal the decrease of SER prevailed over that of the mitochondrial compartment, while the reverse occurred during the remaining three days. The increase in the volume of dense-body compartment, though largely due to the accumulation of residual bodies, was mainly coupled with a rise in the volume of the microautophagic-vacuole compartment during the first two days after ACTH cessation and with an increase in that of the macroautophagic-vacuole compartment during the following three days. The hypothesis is advanced that both micro- and macroautophagy play a role in the reversal of ACTH-induced hypertrophy of rat zona fasciculata cells after cessation of treatment, the first process being mainly involved in the elimination of SER, and the second one in the degradation of mitochondria.     

Nerve repair by means of vein filled with muscle grafts I. Clinical results

Peripheral nerve lesions with a long segment defect need a grafting conduit to heal. Although autogenous nerve grafting is still considered the best method for bridging nerve defects, several alternative types of conduits (biological and synthetic) have been studied. We have demonstrated in previous experimental research in rats that a graft made using a vein (providing a guide for nerve regeneration) filled with fresh skeletal muscle (to prevent vein collapse and support axon regeneration) gave similar results to traditional nerve grafts. On this basis, we decided to use the muscle-vein-combined grafts in clinical cases. From 1993 to 1997, this technique was applied for bridging both sensory and mixed nerve defects (21 cases). We report good results in 85% of our cases with a minimum follow-up of 14 months. These results, obtained on nerve defects ranging from 0.5 to 6 cm in length, seem to be superior to those reported with other kinds of artificial or biological conduits.     

Clinical experience with vestibular schwannomas: epidemiology, symptomatology, diagnosis, and surgical results

The Danish model for vestibular schwannoma (VS) surgery has been influenced by some historical otological events, taking its origin in the fact that the first attempt to remove CPA tumors was performed by an otologist in 1916. In approximately 50 years VS surgery was performed by neurosurgeons in a decentralized model. Highly specialized neuro- and otosurgeons have been included in our team since the early beginning of the centralized Danish model of VS surgery in 1976. Our surgical practice has always been performed on the basis of known and proven knowledge, but we spared no effort to search for innovative procedures. The present paper reflects the experience we have gained in two decades of VS surgery. Our studies on the incidence, symptomatology, diagnosis, expectancy and surgical results are presented. Received: 26 February 1997 / Accepted: 7 July 1997     

Long-term results of surgery for chronic granulating otitis

The late results of planned one-stage procedures in 229 ears with chronic granulating otitis were analyzed, and the justification for two-stage procedures is discussed. All ears were discharging despite intensive preoperative treatment, and all had severe mucosal pathology. The total re-perforation rate was 12%. Five per cent were closed at re-operation, so that at the last follow-up perforations were found in 7% of the ears. The average observation period was 11 years (range, three to 20 years). After one operation, 91% of the ears were dry, and after the re-operations, 98% of the ears were dry. The re-operation rate was 16%. Because of these results obtained by planned one-stage procedures, the authors do not recommend two-stage procedures in non-cholesteatomatous conditions. The authors furthermore conclude that canal-up mastoidectomy is preferable in non-cholesteatomatous granulating otitis.