RSS

Monthly Archives: March 2011

Prognostic Factors of Cutaneous Squamous Cell Carcinoma


Below is a brief description of the prognostic factors involved with cutaneous squamous cell carcinoma, ie. SCC of the skin.

Site

The actual site of the SCC provides much prognostic information, most importantly that SCCs from sites such as the ear, lip and sole have an increased rate of metastasis.

Size

The physical size of the tumour is also related to prognosis, generally speaking the larger the tumour the poorer the prognosis.

Invasion

If the SCC is seen to be invasive this reflects a poorer prognosis. The actual depth of invasion is again prognostic, ie. the deeper the invasion, the poorer the prognosis.

Tumour differentiation

Histologically SCCs are graded for their differentiation with them being either well, moderately or poorly differentiated. The poorer the tumour differentiation, the poorer the prognosis.

Other

There are many other factors which can affect the prognosis of cutaneous squamous cell carcinoma including immune status of the patient, HPV infection status, age and genetic predisposition.

 

Thanks for reading

Keep an eye out for my website soon to be up and running (www.skinpathonline.com)

Follow me on twitter (@skinpathology)

My email is feedback@skinpathonline.com for any questions or queries.

 

Tags: , , , , , , , , , , , , , , , , , , , ,

Non-melanoma skin cancer (NMSC) treatments


Below are the most common treatments available, plus a brief description, once a NMSC has been diagnosed (usually a basal cell carcinoma or a squamous cell carcinoma).

Surgical excision (standard) – the most common and preferred form of treatment. Good for nodular tumours with a sharply demarcated border. Has a high cure rate and is dependent on the closeness of tumour to the resection margin in regards to the pathology (ie. the closer the tumour is to the margin the more likely it is to recur). One let down is the bread loafing technique which results in only approximately 5% of the actual margins being visualised by the pathologist for assessment of complete excision.

Moh’s /  Moh’s Micrographic Surgery – form of treatment with the highest reported cure rate (~97-99%). This technique results in the entire peripheral margins and the deep margins being visualised and assessed for completeness of excision (this is why the cure rate is so high). One let down is the time-consuming nature of the technique and the specialised training that is involved.

Topical chemotherapy – the most common available topical chemotherapy agents include 5-fluorouracil (5-FU) and 5% imiquimod. Generally speaking 5-FU works by inhibiting DNA replication therefore the growth of the tumour and imiquimod works by modifying the local tumour immune response of the patient. Advantages include the non-invasiveness topical therapy. Disadvantages are that, used alone, they can only be used on superficial tumours and not invasive tumours. Experimentation of their use in conjunction with other treatments (eg. curettage then topical treatment, or topical use to reduce tumour size before excision) have resulted in reports of higher cure rates.

Curettage +/- Electrodissection – put simply the tumour is physically scrapped away then the treated area is exposed to an electrical current which results in the softening of the skin and the procedure is repeated until the treating physician is satisfied excision is complete. The curettage portion technique can be applied alone without the electrodissection. This technique is usually reserved for site which are cosmetically unimportant (eg back). The cure rate is dependent on how aggressive the technique is applied (ie. the more the aggressive the higher the cure rate) and the growth type of the tumour being treated (ie. the more invasive the tumour the lower the cure rate).

Cryotherapy – one of the older treaments for NMSC which involves treatment of the tumour most commonly with liquid nitrogen. Cure rate can be high but there is reduced tumour margin control resulting in a higher recurrence rate.

Photodynamic Therapy (PDT) – fairly new technique which involves applying a topical photosensitizer to the target tumour and then exposure of the target area to light. This results in the production of aggressive chemicals which damage the cell causing death. Disadvantages include the ineffectiveness on invasive and thicker tumours due to lack of light penetration, and high cost. Advantages include the non-invasiveness of the technique.

Radiotherapy – usually reserved for older patients or where the surgical removal of the tumour is not a viable option. Has a reported cure rate of approximately 80-95%. Tumours recurring after radiotherapy are generally more aggressive and can become radiotherapy resistant.

I welcome any comments or other therapies you have encountered.

Keep and eye out for www.skinpathonline.com.

Follow me on twitter (@skinpathology)

 

Tags: , , , , , , , , , , , , , , , , , , , ,

Melanoma – Prognostic Factors – Quick Overview


Hi again

I received many questions regarding melanoma and its prognostic factors so I summarised most of the important ones below and have given a brief, general description for each.

AGE – the older the patient, the poorer the prognosis.

SEX – generally females have a better prognosis than males.

BODY SITE – melanomas on the extremities (eg. legs and arms) have a better prognosis than those on the neck, trunk and face.

INVOLVEMENT OF LYMPH NODES – presence of tumour lymph node involvement has a poorer prognosis. Generally the more nodes involved the poorer the prognosis.

TUMOUR THICKNESS – the thicker the melanoma the poorer the prognosis.

ULCERATION – the presence of ulceration indicates a poorer prognosis.

MITOTIC RATE – the higher the mitotic rate the poorer the prognosis.

REGRESSION – presence of regression in thin melanomas indicates a poorer prognosis.

There are a few other prognostic factors such as Clarks level, tumour-infiltrating lymphocytes, BRAF mutations and LDH (lactate dehydrogenase) serum level.

Many thanks for reading and please leave any comments you wish.

Keep an eye out for my website coming soon www.skinpathonline.com

Follow me on twitter as well (@skinpathology)

 

Tags: , , , , , , , , , , , , , , , , ,

Special Stains for Amyloid


Hi once again

Amyloid is a common substance found in the skin, in association with a number of disorders including, lichen amyloidosis, macular amyloidosis and also basal cell carcinoma. Amyloid results from the death of cells (apoptosis).

The presence of amyloid maybe diagnostic (as in the case with lichen amyloidosis) or coincidental (as in basal cell carcinoma where its has no prognostic significance). Since the presence of amyloid is sometimes coincidental there is no need to do a special amyloid stain as it would not add any diagnostic value.

Amyloid can sometimes be easily recognised on a standard H+E stain as amorphous eosinophilic material, especially if it is ubiquitous in the sample. If only small amounts of ?amyloid are present (as may be in the case of lichen amyloidosis) this is where the amyloid special stain can come into play. Since the presence of amyloid can make or break the diagnosis the scientist needs to ensure his/her method and technique is up to scratch.

The Congo Red method, which requires light polarizing equipment, seems to remain the gold standard amongst most laboratories with the thioflavin method also popular. I have included below my favoured method for amyloid as is it very quick, only needs light microscopy and produces a very good visual result.

Crystal Violet

1. Sections to water

2. Stain with crystal violet solution (same as one used in Gram stain) for 2 – 3 mins.

3. Wash in water then diff in very weak (~0.2%) acetic acid for about 5 secs.

4. Wash in water and mount using aqueous mounting media

5. If wanted seal coverslip around the edges with nail varnish.

This is a metachromatic stain with the amyloid appearing pink/purple and the surrounding tissue staining purple.
I would invite anyone to submit their favoured amyloid staining technique along with its advantages and disadvantages.
Many thanks for reading.

Keep and eye out for www.skinpathonline.com COMING SOON

Follow me on twitter (@skinpathology)

 

Tags: , , , , , , , , , , , , , ,

Cutaneous Spindle Cell Tumour Immunohistochemistry Panel


Hello all again,

This post is about cutaneous spindle cell tumours and their immunohistochemistry (IHC) profiles. I get many questions from laboratory staff about why we perform certain IHC and in what situations are they used. Since spindle cell tumours require IHC for their correct specific diagnosis I thought I would do a post on them (plus I was also involved in a recent published journal article about this very subject)

Cutaneous spindle cell tumours include atypical fibroxanthoma (AFX), spindle cell melanoma, leiomyosarcoma and spindle squamous cell carcinoma. Why can’t the pathologist diagnose these tumours simply on H+E without the need for IHC. Well, cutaneous spindle cell tumours look extremely similar on H+E and the possibility of misdiagnosing a spindle cell melanoma (which obviously is extremely serious) as, for example, an AFX (which has a rather benign, indolent clinical course despite it’s alarming histopathology appearance). Below is a table which provides an example panel leading to the diagnosis of AFX and the reasons for the use of each particular antibody.

S100 – Negative. Essential to exclude melanoma.  Also highlights Langerhans cells, which can be prominent in some AFX.

Melan A – Negative    Optional, if S100 is negative.

HMB45 – Negative    Optional, if S100 is negative.

Broad spectrum cytokeratin (e.g. MNF116, AE1 & 3) – Negative   Beware of included normal adnexal structures or hyperplastic epidermal downgrowths.

34betaE12 – Negative    Highlights some squamous cell carcinomas more prominently than broad spectrum cytokeratins.

Smooth muscle actin – Positive    ~75% of AFX tumors are positive.

Desmin – Negative    Useful to exclude leiomyosarcoma in actin positive cases.

CD68 – Positive    ~90% of AFX tumors are positive.

CD10 – Positive    Although most AFX are positive, the specificity of this antibody is low, making it of limited discriminatory value.

At a minimum an S100 ( to exclude melanoma), CD68 (positive for AFX), a keratin (preferably 34betaE12 as this stains most spindle squamous cell carcinomas) and desmin (positive for leiomyosarcoma), should be performed on all cutaneous spindle cell tumours.

Thanks for reading and I invite any questions or comments, email me them if you want (feedback@skinpathonline.com)

Keep an eye out for my up and coming skin pathology website (www.skinpathonline.com)

Follow me on twitter (@skinpathology)

 

Tags: , , , , , , , , , , , , , ,

The Need For Greater Education of Medical Scientists in Histopathology Laboratories


Hello again

This is my second post and I want to thank all that read and commented on my first post. As you can tell from the title I am an advocate for the ongoing job-specific training of medical / biomedical scientists in pathology and in particular histopathology (as this is the area of which I am involved).

By “job-specific” I really do mean that. My experience with ongoing education of medical scientists within many laboratories involves mainly attending conferences which in fact do provide presentations on many interesting and varying medical subjects but do not translate into increased knowledge within the pathology sector that they are employed. Yet attendance at these conferences do fulfill the “ongoing education” condition of governing accreditation bodies. For example a conference attended by this author attended by many medical scientists of employed over all the different disciplines (eg. histology, microbiology, haematology), had many interesting talks (eg. the effect of a local major natural disaster and the providing of medical assistance from neighbouring countries), but he could not see how these talks would translate to increased laboratory knowledge beneficial to the conference attendee.

It appears to this author that there is very limited opportunities offered to pathology laboratory employees which in turn is resulting in these employees not possessing an ever-growing knowledge base of their chosen discipline. Another example observed by this author is the huge majority of histopathology scientists not being able to recognise the simplest of skin tumours histologically (eg. BCC, SCC, melanoma), which is the ‘bread and butter’ of skin pathology.

What is the purpose of scientists being able to recognise tumours histologically I hear you say? If scientists can recognise these simplest of tumours, this talent can be put to a number of uses including cutting deeper levels on initial sections that are non-diagnostic before the initial sections are given to the pathologist thus increasing the efficiency of reporting. This example of course depends on the confidence of the pathologist to trust the scientist to recognise a case that requires deeper levels.

Thank you very much for reading this post and hopefully you found it of interest.

PS. keep a look out for www.skinpathonline.com (up and running soon)

Follow me on twitter (@skinpathology)

Any questions / queries email me feedback@skinpathonline.com

 

Tags: , , , , , ,

Sentinel Lymph Node Biopsy. Is it useful?


Hi everybody,

Well I did say that my next blog post would be in a weeks time but I have recently read an article that caught my eye and somewhat relates to skin pathology.

The article was entitled  ‘Axillary Dissection vs No Axillary Dissection in Women With Invasive Breast Cancer and Sentinel Node Metastasis’ and was in the February 9th, 2011 issue of the Journal of the American Medical Association. Although this relates to patients with breast cancer I wonder if there will be any overflow of this argument into the ongoing debate over the use of sentinel lymph node biopsy (SLNB) with regards to patients with melanoma.

The results of the aforementioned study showed “among patients with limited sentinel lymph node (SLN) metastatic breast cancer treated with breast conservation and systemic therapy, the use of SLND (sentinel lymph node dissection) alone compared with ALND (axillary lymph node dissection) did not result in inferior survival.” This result has also been mirrored in multiple melanoma SLNB studies. Many people have and still continue to argue over the pros (eg. without a SLNB it is not possible to accurately stage melanoma according to international guidelines) and cons (eg. the impact of complete lymph node dissection (CLND) on a patient’s immune capability).

I wonder if in the future SLNB will remain standard practice or if it was a good idea at the time.

Many thanks for reading and hopefully this post will get some interesting comments and I am sure it will.

Also don’t forget to follow me on twitter (@skinpathology)

Paul Drury

http://www.skinpathonline.com (will be up in the near future)

PS. This is the link for the JAMA article (http://jama.ama-assn.org/content/305/6/569.abstract)

 
5 Comments

Posted by on March 1, 2011 in Uncategorized

 

Tags: , , , , , , , , , ,