Small cell, low grade lymphoma

Re: Small cell, low grade lymphoma

Gerry Polton — Wed, 09 Jul 2014 09:02:53 GMT

Hi Bob

This is curious. I would not expect such rapid progression in a case with a low grade spindle cell sarcoma. This forces us to consider whether the histological diagnosis really reflects the nature of the underlying problem. Remember that histological grade is an expression of what a tumour looks like which we then presume to be a satisfactory proxy marker of what the future holds. Often this is correct. Sometimes it is not. Having said that, it is often better to base our estimates of prognosis on something shaky than on nothing at all. If the story in this case was of a dog who had undergone a similar incomplete excision two years ago and now the mass was back, I would not hesitate in recommending revision (cytoreductive) surgery and simply waiting patiently for it to come back yet again. Like you, I do think that strategy still has something to offer this patient. However, I also wonder whether we should be considering amputation right now. I have an uncomfortable feeling about this case. I don't believe that metastasis is even remotely likely. However, I do believe that a further cytoreductive procedure at this stage might result in a further similar discussion about addressing the local recurrence of this tumour in a distressingly short period of time. I would at least have a conversation with the owner in which that possibility is presented. If they would prefer to keep the dog's leg for now despite that, then so be it. Hopefully a further surgery will achieve a more durable remission this time.

Good luck

Gerry

Re: Small cell, low grade lymphoma

Bob Russell — Tue, 08 Jul 2014 15:33:58 GMT

Microscopic Description:

Mass from foreleg (6 sections). Expanding the dermis and the subcutis, and extending to the tissue edges is a densely cellular, poorly demarcated and non encapsulated neoplastic mass. The neoplastic cells are arranged in short interlacing streams and bundles, that often form whorls around capillaries and collagen. In some areas the neoplastic cells are closely packed and separated by a small amount of collagenous matrix and in other areas the cells are more widely separated and surrounded by a pale, loose, amphophilic matrix. Individually, the neoplastic cells are spindled, have variably distinct cell borders, scant eosinophilic fibrillar cytoplasm, and round to elongate nuclei with finely stippled chromatin and 1 to 2 variably distinct nucleoli. Anisocytosis and anisokaryosis are mild to moderate, and some multinucleated giant cells are noted. Mitoses are 4 in 10 high power fields. Occasionally there are variably sized clefts partially separating neoplastic cells. Multifocally there are clusters of small lymphocytes and lesser plasma cells.

Histological Diagnosis:

Soft tissue sarcoma, low grade, mass from fore leg.

Comment:

This mass from the leg is a neoplastic proliferation of mesenchymal origin, most representative of a low grade soft tissue sarcoma. Given the cellular characteristics and arrangements, a peripheral nerve sheath tumour would be the most likely diagnosis. The main differential would be a perivascular wall tumour. In any case, and given the histological grade, this tumour is expected to be locally aggressive and infiltrative, but would not be expected to metastasise. As the neoplastic cells extend to the tissue edges, local recurrence is likely.

A 15mm diameter swelling is now evident at the distal end of the scar. If it were my dog I would probably repeat surgery and path and amputate later on the grounds that the dog is probably better keeping four legs as long as possible to reduce wear and tear problems with the unaffected leg. This is probably not an option as the total insurance per condition is only £1500!

Size of mass prior to surgery 4cm diameter.

Many thanks for the advice !!

Re: Small cell, low grade lymphoma

Gerry Polton — Tue, 08 Jul 2014 14:56:03 GMT

Hi again, Bob,

On the basis of the fast rate of relapse I assume this is a high-grade or intermediate-grade soft tissue sarcoma. Options for management include amputation, as you have mentioned, as well as revision surgery, revision surgery plus radiotherapy, metronomic chemotherapy or possibly radiotherapy alone though I would be anxious about that last one as an option as it feels a bit high-risk, low return.

If you have any more information that might help. Information of interest includes the wording of the histology report, size of the mass and time between surgery and relapse.

Gerry

Re: Small cell, low grade lymphoma

Bob Russell — Tue, 08 Jul 2014 13:44:52 GMT

Nope - lurcher!

Re: Small cell, low grade lymphoma

Rob Loxley — Tue, 08 Jul 2014 13:37:56 GMT

Is it a cat? if so could oncept be used?

Re: Small cell, low grade lymphoma

Bob Russell — Tue, 08 Jul 2014 13:05:55 GMT

Brilliant - many thanks! Just wanted to check!

Bob

Next one! - soft tissue sarcoma on foreleg below elbow. Was originally removed for biopsy as FNA only yielded fluid. Thought was a cyst but clearly not!

Was invasive into deep structures and has returned rapidly. Alternatives to amputation?

Re: Small cell, low grade lymphoma

Gerry Polton — Tue, 08 Jul 2014 12:52:29 GMT

Hi Bob

To answer the question you put at the end, the treatment option of choice is NO TREATMENT. Apologies for the capitals, they were meant for emphasis but not to suggest being shouty. It's a surprise but treating these cases with steroids alone gave a 25 times (yes 25 times) greater risk of death than no treatment at all!! COP treatment gave a 3.25 times greater risk of death than no treatment and doxorubicin based chemotherapy gave a 2 times greater risk of death than no treatment at all. Would you Adam and Eve it???

The received wisdom (for what it is worth) is that these patients are best left untreated until their lymphoma appears to be making them feel poorly. They can live in excess of two years without any treatment at all but with big lymph nodes. Big can mean navel orange size in a Jack Russell. Many owners struggle with the idea of not treating these. Once the cancer appears to be progressing more quickly and causing the dog to feel unwell, we tend to treat with a doxorubicin based protocol if we treat them at all. For many owners they are comfortable simply requesting euthanasia at this time.

Please consider the possibility that this low grade illness has been present for a long time. Although cases can, and regularly do live for in excess of two years without therapy from the time of diagnosis, this does depend on us making a diagnosis once the disease is first detectable. Quite a few of these cases are diagnosed at an annual vaccination and health check. It is quite conceivable that those patients have had a peripheral lymphadenopathy for ten or eleven months by that stage (or more...?) so the two years or so rule might still apply but might have to be back-dated.

Best wishes

Gerry