NATIONAL RENAL PATHOLOGY EQA SCHEME

Report of Participants' Meeting

Thursday 22nd September 2004

In the Robin Brook Centre, St Bartholomew’s Hospital

18 participants were present.

Professor Furness opened the meeting by reminding participants of the purpose of the meeting.  He invited comments on the running of the EQA Scheme and suggestions for improvement, either at the meeting or in writing later.  No suggestions were received.

The cases in circulation P and Q were discussed, as follows.

Circulation P

P218

This was a case of lymphomatous infiltration of the kidney, though as only a H&E section was circulated precise phenotyping was impossible.  The most popular diagnoses was “lymphoma NOS”.

Participants agreed that the suggested diagnoses “Sarcomatoid carcinoma, do immuno” and “malignant tumour, do immuno” were insufficiently precise, but in view of the “do immuno” instruction it was clear that a correct diagnosis would have been reached if relevant immunohistochemistry had been included with the material for circulation.  These diagnoses were therefore awarded half marks.

“Granulomatous inflammation, exclude TB if not monoclonal” was regarded as wrong.  However, a participant present explained that he had provided this diagnostic category in error, having intended merely to raise the possibility of simultaneous TB in a patient with lymphoma.

P219

This was a case of scleroderma.  Histologically, the appearance was of a thrombotic microangiopathy – one participant present suggested that “malignant vascular injury” might be a better term as the insult is not limited to the microcirculation. 

A confident diagnosis of systemic sclerosis requires correlation between the pathological information and the clinical information.  In this case the clinical information provided was not entirely typical.  After a vote it was decided that the first four diagnostic categories should be merged and regarded as correct.  The diagnostic category “Mucoid vasculopathy and ischaemia” was proffered by one participant.  The meeting was uncertain what was meant by this term, and therefore agreed that this diagnostic category should be awarded half marks for personal scoring.

P220

This was a straightforward case of diabetic nephropathy.  The meeting agreed that the first two diagnostic categories should be merged, as it was perfectly reasonable to raise the possibility of simultaneous glomerulonephritis and request electron microscopy.  However, the single participant who made a confident diagnosis of mesangiocapillary glomerulonephritis type I was deemed to have made a mistake, even though that participant simultaneously commented on the presence of diabetic nephropathy.

P221

This was a case of lupus nephropathy, as confirmed by subsequent information from the submitting pathologist.  The relatively consistent grading as “lupus IV” by participants was noted as representing better reproducibility than we have previously seen in the EQA scheme when the WHO classification is applied.  It was agreed that any diagnostic category which suggested lupus would be regarded as correct for personal scoring; no other changes would be made. 

The large number of participants who indicated the need to know the lupus serology with electron microscopy and a silver stain was noted, but in view of the presence of typical lesions on the H&E section (including “wire loops”) the case was nevertheless regarded as suitable for personal scoring. 

P222

This was a patient with established vasculitis in 2000 and creatinine now increasing.  After some discussion as to how the level of disease activity should be reported by pathologists, the meeting agreed on the basis of a vote that the first three diagnostic categories should be merged and regarded as correct.  Hence any diagnosis which indicated a vasculitis process as the main problem was regarded as correct.  The other diagnoses proffered was regarded as incorrect. 

Two participants had declined to offer a diagnosis on the basis that they could not view the images circulated on CD.  One participant present at the meeting explained the difficulties encountered opening the CD as a result of antiquated NHS IT equipment and inadequate software.  The meeting therefore regarded this response as legitimate, and the Organiser will delete these responses from the database before calculating personal scores, so that participants who were unable to open the CD will not be penalised for not offering a diagnosis.

 

Professor Furness indicated that he took this as evidence that circulating images on CD was probably inappropriate for future circulations.  Participants who regard this as inappropriate are invited to comment and make constructive suggestions.

P223

The consensus diagnosis in this case was of an interstitial nephritis, with a high proportion of participants pointing out that pyelonephritis needed to be excluded.

However, discussion of this case was not straightforward.  There was a debate about the use and definition of the term “interstitial nephritis”.  One participant present pointed out that in this case, the interstitial lymphocytic infiltrate was somewhat patchy and he had been unable to find any evidence of lymphocytic infiltration of the epithelial compartment of the tubules.  He suggested that “interstitial nephritis” is a term which should not be used, as interstitial inflammation is a component of almost any renal disease, and that “tubulo-interstitial nephritis” should be used to designate the process which is typically caused by an idiosyncratic reaction to drugs. 

A lengthy discussion followed.  After a vote, it was agreed that this case should not be used for personal scoring.

Professor Furness suggested that this case should be highlighted on the NEPHNPPT e-mail discussion group for renal pathology,  to gain an international perspective of how renal pathologists believe the terms “interstitial nephritis” and “tubulo-interstitial nephritis” should be used, and whether a diagnosis is tenable in the absence of lymphocytic infiltration of tubules.  The meeting agreed.

EQA participants who would like to participate in this debate are invited to subscribe to the NEPHNPPT mailing list.  This can be achieved by sending an e-mail to majordomo@majordomo.srv.ualberta.ca , leaving the subject line of the e-mail blank and including the text “subscribe nephnppt” in the body of the message.

Circulation Q

Q224

This was a case (as reported by the submitting pathologist) of necrotising glomerulonephritis in the context of mixed connective tissue disease.  The most popular diagnostic category was indeed mixed connective tissue disease, but with a popularity barely greater than 3/10.  A large proportion of participants had interpreted the histology as suggesting a diagnosis of lupus.  It was suggested at the meeting that to make a diagnosis of mixed connective tissue disease required a correct interpretation of the immunological investigations provided in the clinical information.

If the correct diagnosis was to be regarded as mixed connective tissue disease, the proportion of participants making that diagnosis was too low for this case to be included for personal scoring in an EQA scheme.  The participants at the meeting discussed this problem, and agreed that diagnostic categories mentioning lupus nephritis should be merged with the diagnosis of mixed connective tissue disease under “MCTD/lupus” and regarded as correct.

Q225

This was a case of acute tubulo-interstitial nephritis, almost certainly secondary to the antibiotic treatment reported in the clinical information.

The participants agreed that the first three diagnostic categories and the eighth (granulomatous interstitial nephritis) should be merged into a single category of tubulo-interstitial nephritis and regarded as correct.

There was some discussion of how to handle diagnostic categories 6 and 7, where diabetes (6) or glomerulonephritis (7) were reported in combination with tubulo-interstitial nephritis.  After some discussion the participants at the meeting agreed that the morphological evidence of diabetic nephropathy and glomerulonephritis was essentially absent and these diagnostic categories should be awarded one quarter marks. 

Q226

This was a straightforward case of myeloma cast nephropathy.  Some participants had raised the question of whether the lymphocytic infiltration in the interstitium might include a component of malignant cells; these two diagnostic categories would be merged for purposes of personal scoring.  The third diagnostic category (pyelonephritis) was regarded as incorrect.

Q228

All participants had identified this case as representing membranous glomerulonephritis.

Q229

This was another case of tubulo-interstitial nephritis.  It was agreed that all diagnostic categories mentioning interstitial nephritis would be merged and regarded as correct, with one exception.

Professor Furness specifically asked the meeting to consider diagnostic categories 2 and 6.  He pointed out that tubulo-interstitial nephritis is associated with tubular damage, which one might choose to refer to as “secondary acute tubular necrosis”.  However, genuine acute tubular necrosis (due to ischaemic, toxic or other insults) is usually associated with a (relatively light) interstitial infiltrate of mononuclear cells and it is the task of the pathologist to try to identify which is the underlying pathologic process.  Consequently, although “interstitial nephritis and ATN” sounds very similar to “ATN with interstitial nephritis”, the latter diagnosis suggests that acute tubular necrosis is the principal underlying process.  After the ensuing discussion, the participants present agreed that “ATN with interstitial nephritis” implied incorrectly that the main pathologic process was acute tubular necrosis.  It was therefore agreed that this diagnostic category should be awarded half marks.

Other Business

Professor Furness reported that he is now in a position to set up an internet-based system for responding to Renal Pathology EQA cases.  It would be technically possible, with a relatively small amount of work, to put pages on the scheme’s web-site whereby participants could enter their diagnosis on screen.  On clicking a “submit” button the diagnoses would be sent to Professor Furness electronically, associated only with the participants number and not with any further identifying details.

Professor Furness asked the participants present whether this facility had any value.  Would participants use it?  There was little enthusiasm amongst the participants present, and one participant commented that a local general EQA scheme has initiated internet-based reporting of this type, but it is very little used.

On this basis it was agreed that Professor Furness would not implement an internet-based system for responding to renal EQA cases.  However, participants who were not present at the meeting are invited to make their views known to the scheme organiser.

Participation / CPD certificates for returning responses will be posted to participants in about 2 weeks.  However,  Professor Furness apologised for failing to provide additional CPD certificates for participants who were present at the meeting.  Anyone who attended the meeting and wishes to have a CPD certificate confirming attendance, please e-mail Professor Furness on peter.furness@le.ac.uk

The meeting closed at 2.30pm.