Insights into Enchondroma, Enchondromatosis and the risk of secondary Chondrosarcoma. Review of the literature with an emphasis on the clinical behaviour, radiology, malignant transformation and the follow up

The Enchondroma is a common, benign, cartilage forming tumour. They usually occur as a single, asymptomatic lesion. Occasionally patients present with multiple enchondromas which is generally defined as enchondromatosis. This entity encompasses several different subtypes including Ollier disease and Maffucci syndrome (enchondromatosis associated with soft tissue haemangiomas) as the most commons. Some of them have a complicated clinical course when malignant transformation occurs. This malignant progression is a well known fact especially in enchondromatosis, but up to now there is still a lack of recommendations concerning the follow up. The aim of this article is to review the clinical and imaging features of patients with solitary enchondroma and enchondromatosis focusing on the development of secondary chondrosarcoma and the follow up.

[Osteochondroma and multiple osteochondromas: recommendations on the diagnostics and follow-up with special consideration to the occurrence of secondary chondrosarcoma]

PURPOSE

Osteochondroma represents the most common form of benign bone tumor. Clinical manifestations include deformity of bone, compression of surrounding tissue and vascular or neurological compromise. Osteochondromas may be solitary (solitary osteochondroma, SO) or multiple (multiple osteochondromas MO). Recurrence after surgery is a known problem especially in MO and malignant transformation is rare but more common in MO than in solitary cases. Reliable recommendations regarding diagnostics and clinical follow-up are currently lacking.

PATIENTS AND METHODS

A comprehensive literature review and a review of own patient files with SO/MO treated between 2000 and 2011 in this hospital were performed. The age of patients at diagnosis, tumor localization, clinical aspects, recurrence and the risk of malignant transformation in secondary (i.e. epiexostotic) chondrosarcoma were analyzed. The follow-up including patients who received surgery ranged between 2 and 127 months for patients with SO and between 2 and 84 months for MO.

RESULTS

A total of 39 patients with SO from this hospital were included in the study. Out of 36 patients who received surgery 3 recurrences were registered after an average time of 62 months. In addition, 11 patients with MO were identified and all received surgery. In 5 out of 11 cases recurrences occurred after an average time of 20.6 months. Secondary chondrosarcomas were not recorded in this series. According to the literature an increased risk of malignant transformation was found for osteochondromas of the axial skeleton, in the proximal aspect of the extremities, as well as for recurrent tumors and for MO. Pain and/or increase in size of lesions after skeletal maturation were the most common clinical signs of transformation. There was a wide time interval between the initial diagnosis and the development of secondary chondrosarcoma. In MO secondary chondrosarcoma has been described before skeletal maturity.

CONCLUSIONS

The risk of malignant transformation of SO is generally low. Axial lesions as well as recurrent osteochondromas and MO seem to have an increased risk of malignant transformation. The follow-up, requiring sufficient primary diagnostics, includes regular self-control and can usually be clinically carried out in more peripherally located lesions but in certain cases supplementary X-ray imaging is needed. In cases of anatomical regions which are more difficult to access manually, follow-up examination by magnetic resonance imaging (MRI) is the method of choice. Especially MO patients seem to benefit from long-term follow-up: when the tumor is located in the trunk and in (proximal) long bones MRI or whole-body MRI, respectively, should be performed once a year after skeletal maturity because of the higher risk of malignant transformation in these patients.

Epithelioid osteosarcoma of the scapula

Epithelioid and epithelial neoplasms of bone are rare. They include different epithelioid variants of vascular lesions, osteoblastoma, chondroblastoma and most importantly metastatic carcinoma. Up to now, only few cases of epithelioid osteosarcoma were described. In this case the authors report a 53-year-old patient presented with a medical history of chronic shoulder pain for 3 years. Magnetic resonance imaging (MRI and computed tomography (CT) showed a destructive, partially calcified osseous lesion of the scapula with expansion into the surrounding soft tissue, suggestive of a primary bone tumor. Histologically, the tumor consisted of epithelioid cells with expression of cytokeratine and the lesion was primarily diagnosed as metastatic carcinoma. With regard to the MRI morphology untypical for metastatic disease the histopathologic slides were re-evaluated and detection of tumor osteoid led to the diagnosis of epithelioid osteosarcoma. Chemotherapy was initiated, however follow-up imaging studies showed rapidly progressive disease of both primary tumor and lung metastases. In conclusion, epithelioid neoplasms of the bone are extremetumourly rare and must be distinguished from metastatic carcinoma. Despite the presence of cytokeratine positive cells a thorough histological evaluation is mandatory and osteoid detection is essential in order to establish the correct diagnosis and further treatment. Key words: osteosarcoma, epithelioid, aneurysmal bone cyst, chondrosarcoma, pathology, immunohistochemistry.

High-grade glioma: refined diagnostics steering stratified therapy

An adequately sampled tumor histology that is evaluated by an experienced neuropathologist is the current international standard for the diagnosis of high-grade gliomas. We present the case of a 30-year-old female for whom clinical and radiological information dramatically changed the histological diagnosis. We suggest a new algorithm including these parameters to refine the accuracy of histological diagnosis both for standard treatment and centrally reviewed clinical trials.

The many faces of chondrosarcoma of bone, own cases and review of the literature with an emphasis on radiology, pathology and treatment

Chondrosarcoma is the third most frequent primary malignant tumor of bone, constituting up to 16% of the malignant osseous neoplasms. Up to date several genetic alterations and markers were described concerning the pathogenesis and the progression of the chondrosarcoma, which represents actually a heterogeneous group of different types including conventional intramedullary, clear cell, myxoid, mesenchymal, and dedifferentiated chondrosarcoma. The pathologic appearance varies, however, in general they grow with a lobulated pattern. Histologically the hyaline cartilage demonstrates high water content and typically enchondral ossification is apparent. Imaging reflect this while radiographic findings suggest the diagnosis when the typical "ring-and-arc" chondroid matrix mineralization, endosteal scalloping and soft-tissue extension were apparent. The CT is used for detecting the mineralization of the matrix, especially when it is subtle or when the lesion is located in complex areas. MRT is the method of choice to detect the high water content of these lesions with a high signal intensity with T2-weighting and its bone marrow extend. Surgical resection is the primary and preferred treatment modality for most individuals with localized disease. In selected cases of the Grad I conventional chondrosarcoma curettage should be discussed. Systemic chemotherapy may be considered in variant forms such as mesenchymal or dedifferentiated chondrosarcomas. In knowledge of the "many faces" of the primary chondrosarcoma individualized patient assessment and optimal clinical management is possible.

[Radiological procedures in the traumatised wrist]

Injuries of the wrist are difficult to diagnose because of the complex and narrow anatomic structures. On the basis of precise clinical examination, X-rays, CT and MRI are valuable additional tools that can be used. In the case of bone injury, spiral computer tomography with multiplanar reformatting is currently the method of choice. MRI is indicated for the identification of soft tissue or ligamentous injury and avital fragments or necrosis. Other diagnostic tools for the wrist are currently of minor importance. Technical and methodological innovations allow ever better visualisation and classification of lesions, as well as their extent, thus enabling more targeted therapy. However, prerequisites of effective use include differential assessment and precise knowledge of the procedures.

Vertical distribution of organochlorine pesticides in humus along Alpine altitudinal profiles in relation to ambiental parameters

In forest soils along vertical profiles located in different parts of the Alps, concentrations of persistent organic pollutants (POPs), namely organochlorine pesticides (OCPs) like dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCH), heptachlor, aldrin, dieldrin and mirex, were measured. Though local characteristics of the sites are influenced by numerous factors like orographic and meteorological parameters, forest stand characteristics and humus parameters, we ascertained a marked vertical increase of concentrations of some organochlorine compounds in the soil. On the basis of climatological values of each site, we found that the contamination increase with altitude can be ascribed to a certain 'cold condensation effect'. In addition, the perennial atmospheric deposition of POPs is controlled by precipitation. Other key parameters explaining the accumulation of POPs are the soil organic carbon stocks, the turnover times, the re-volatilisation and degradation processes, which vary with altitude.

PCDD/F and PCB in spruce forests of the Alps

PCDD/F and PCB concentrations in remote mountainous spruce stands of the Central European Alps show strong geographic variation. Independent of the matrix (0.5 year old needles, humus or mineral soil), the highest pollutant levels were always found at the lateral zones of the mountain range. High levels coincided with strong precipitation, particularly along the northern margin of the study region. The most volatile PCB congener propagated farther into the colder, drier central Alps than the heavier species. Matrices with different accumulation history (needles and humus) repeatedly reflected different spatial emission patterns. Consistent with its much longer exposure, pollutant levels in humus exceeded those of needles by up to two orders of magnitude. Needle contamination varied with altitude but the vertical trends were highly variable between transsects and changed between years, too.

A comparison of Alpine emissions to forest soil and spruce needle loads for persistent organic pollutants (POPs)

The project MONARPOP analysed the concentrations of semivolatile organic compounds (SVOCs) in two important sink compartments, needles of Norway spruce (Picea abies [L.] Karst.) and forest soil from 40 remote Alpine forest sites in Austria, Germany, Italy, Slovenia and Switzerland. In the present study the load of PCDD/F, PCB, PBDE, PAH, HCB, HCH and DDT in the Alps calculated on the basis of measured data are compared with their estimated emissions in the Alpine region. It comes out that the masses of the studied pollutants stored in the forests are higher than the corresponding emissions in the Alpine area indicating that the Alps are a sink for POPs advected from surrounding areas. It is assumed that local emissions of PCDD/F and PAH deriving from biomass burning are probably underestimated and that the pool of these pollutants in the forests represents the accumulation over some decades.

[The percutaneous bone biopsy: in vitro study for comparison of bone biopsy needles]

PURPOSE

The aim of this study was to assess the differences in ease of use and quality of samples of several bone biopsy needles in an animal test.

MATERIALS AND METHODS

An evaluation of eight bone biopsy needles of different gauges was undertaken. With each needle, 5 biopsies of an animal bone (lumbal vertebral body of calf, pig and lamb) were performed and compared to each other. The subjective assessment of force to obtain a sample, ease of needle use and ease of sample removal were graded on a 5-point scale. Each biopsy specimen was measured before and after fixation and the gross state was evaluated. For evaluation of histopathological quality, width and degree of fragmentation were also evaluated on a scale.

RESULTS

The Somatex, Bone Marrow and Safe Cut 8 G and the Cardinal Health, Jamshidi 8 G needles were rated as being the easiest ones to use, while the Bloodline, Easy Trap 8 G and the RADI, Bonopty 15 G biopsy needles were rated as being the most difficult ones. Histological specimen quality was highest for the Somatex 8 G needles, the Cardinal Health, Jamshidi 8 G and the Bloodline, Easy Trap 8 G needles. The Inter.V, SnareLok 8 G and the RADI, Bonopty 15 G needles had the lowest yield. Furthermore, differences in length before and after fixation were recorded. The average decrease of core length after fixation was 18 %.

CONCLUSION

The bone biopsy needles tested here vary significantly in performance and quality of the histopathological specimen. Detailed knowledge of the strengths and weaknesses of different needles could facilitate the decision for the selection of an appropriate instrument.

[Radiological procedures in the traumatised wrist]

Injuries of the wrist are difficult to diagnose because of the complex and narrow anatomic structures. On the basis of precise clinical examination, X-rays, CT and MRI are valuable additional tools that can be used. In the case of bone injury, spiral computer tomography with multiplanar reformatting is currently the method of choice. MRI is indicated for the identification of soft tissue or ligamentous injury and avital fragments or necrosis. Other diagnostic tools for the wrist are currently of minor importance. Technical and methodological innovations allow ever better visualisation and classification of lesions, as well as their extent, thus enabling more targeted therapy. However, prerequisites of effective use include differential assessment and precise knowledge of the procedures.

Modelling of biofilters for ammonium reduction in combined sewer overflow

Biofiltration has proved to be a useful system to treat combined sewer overflow (CSO). The study presented uses numerical simulation to detect the critical operating conditions of the filter. The multi-component reactive transport module CW2D was used for the simulation study. Single-event simulations of lab-scale-column experiments with varying boundary conditions regarding the throttle outflow rate were carried out. For the calibration of the CW2D model measurement results of four experiments in two lab-scale columns were used. The model was validated by simulating four events of two further columns filled with the same filter material. These columns were operating with higher throttle outflow rates than the columns used for calibration. For ammonium (NH(4)-N) a good fit between measured and simulated data could be achieved. However, the comparison of simulated and measured effluent concentrations of nitrate (NO(3)-N) showed that there is a need for further investigations mainly due to the uncertainties in the degradation process during dry periods between the loadings.

Antigen persistence is required for dendritic cell licensing and CD8+ T cell cross-priming

It has been demonstrated that CD4(+) T cells require Ag persistence to achieve effective priming, whereas CD8(+) T cells are on "autopilot" after only a brief exposure. This finding presents a disturbing conundrum as it does not account for situations in which CD8(+) T cells require CD4(+) T cell help. We used a physiologic in vivo model to study the requirement of Ag persistence for the cross-priming of minor histocompatibility Ag-specific CD8(+) T cells. We report inefficient cross-priming in situations in which male cells are rapidly cleared. Strikingly, the failure to achieve robust CD8(+) T cell activation is not due to a problem with cross-presentation. In fact, by providing "extra help" in the form of dendritic cells (DCs) loaded with MHC class II peptide, it was possible to achieve robust activation of CD8(+) T cells. Our data suggest that the "licensing" of cross-presenting DCs does not occur during their initial encounter with CD4(+) T cells, thus accounting for the requirement for Ag persistence and suggesting that DCs make multiple interactions with CD8(+) T cells during the priming phase. These findings imply that long-lived Ag is critical for efficient vaccination protocols in which the CD8(+) T cell response is helper-dependent.

[What is the value of the whole body spiral CT in the primary radiological imaging of severely injured children?]

AIM

Whole body spiral CT scans have become a routine method in the radiological imaging of severely injured patients in emergency rooms of an increasing number of hospitals. The routine use of CT scans is, however, still discussed controversially, especially with regard to its use in children. This is mainly due to the reportedly higher level of exposure to radiation of CT scans as compared to plain radiographs. The aim of the present study was to compare the dose of exposure to radiation of a whole body CT scan to that of a plain radiograph protocol in an animal model for severely injured children.

MATERIAL AND METHODS

We chose 3 female pigs of different weights to serve as a model for children at different ages. 4 film radiation dosimeters (positioned on the eye, under the breast, paravertebrally on the thoracic spine and in the small pelvis, respectively) were implanted into every pig for each examination. Plain radiographs of the chest and the pelvis in one plane and of the skull and the complete spine in two planes were performed. The CT scan included skull, cervical spine and the whole body from the thorax to pelvis.

RESULTS

The radiation dose of CT scans was 7 times higher as compared to the X-ray protocol, but the performance of CT scans was faster (8 vs. 18 min). The radiation dose of the whole body CT scan was at about 15 mSv.

CONCLUSION

Based on our data and a review of the literature we will use whole body spiral CT scans as the preferred method in the primary radiological imaging of severely injured patients. In our opinion, the evident benefit of a reduced time of imaging in combination with superior image information outweighs the higher level of exposure to radiation.

Ultrasonography in the assessment of peripheral joint involvement in psoriatic arthritis : a comparison with radiography, MRI and scintigraphy

The objective of our study was to investigate the role of musculoskeletal ultrasound (US) in the assessment of hand and foot small joints in psoriatic arthritis (PsA). Thirteen consecutive patients with PsA of hands or feet underwent B-mode US using a 9- to 13-MHz transducer and simultaneous magnetic resonance imaging (MRI), bone scintigraphy and radiography. US findings were compared with radiography, MRI and scintigraphy in 190, 182 and 109 joints, respectively. To assess the sensitivity and specificity of US, radiography was considered as gold standard for the detection of erosions and osteoproliferations and MRI as gold standard for the detection of joint effusion and synovitis. US, MRI and scintigraphy had a higher sensitivity in the detection of overall joint pathology than radiography in painful and/or swollen joints (71%, 72%, 82% vs 32%) and clinically unaffected joints (17%, 21%, 9% vs 2%). US and radiography detected more erosions and osteoproliferations than MRI, with low agreement between the methods in the detection of erosions. Radiography was superior to US in the visualisation of osteoproliferations. Joint effusions and/or synovitis were more frequently detected by MRI than US. Agreement between both imaging methods was better in carpal joints, carpometacarpal joint I, metacarpophalangeal (MCP)/metatarsophalangeal (MTP) joint I, II and V than in MCP/MTP III, IV, PIP and DIP joints. Compared with MRI, radiography and scintigraphy, the specificity of US ranges between 0.84 and 0.94, depending on the joint pathology. In conclusion, the diagnostic sensitivity of US in the detection of PsA-related synovitis of hands and feet is lower than MRI and depends on the joint region. However, the low cost and the acceptable specificity suggest that US is a useful imaging method in addition to radiography in PsA of hands and feet.

Mural inflammatory hyperenhancement in MRI of giant cell (temporal) arteritis resolves under corticosteroid treatment

OBJECTIVE

To determine the effect of corticosteroid treatment on mural inflammatory hyperenhancement in MRI in GCA.

METHODS

MRI of the superficial temporal artery with sub-millimetre in-plane spatial resolution (195 x 260 microm) was performed in 17 patients with proven GCA at the initiation of corticosteroid treatment and after 16 months of therapy. Visual MRI scores for mural inflammation were correlated with clinical and laboratory findings.

RESULTS

Intensity of inflammatory hyperenhancement decreased significantly under corticosteroid therapy (2.3 +/- 0.6 vs 0.5 +/- 0.6, P < 0.001, with MRI score >2 indicating vasculitis). This finding correlated with the clinical and serological remission in 15/17 patients. Of the two patients with active disease, one had persisting mural inflammation in MRI indicative of relapsing disease. The other patient presenting with signs of polymyalgia rheumatica had no inflammatory changes of the superficial temporal arteries on MRI scan at follow-up.

CONCLUSIONS

Mural contrast enhancement in high-resolution MRI is pronounced in active disease and decreases under corticosteroid treatment, correlating well with laboratory remission.