Re: Bone Cancer

[Pieter.Depuydt@rug.ac.be]

> Pieter.Depuydt@rug.ac.be wrote
> >
> >In David Norman's Illustrated Encyclopedia of Dinosaurs there is 
> >mention of a Chasmosaurus skull with small, rounded 'holes ' in it; 
> >the appearance of these small bone defects is very similar to those 
> >seen in the disease 'multiple myeloma' in humans (so called 
> >'punched-out lesions': small, rounded, clearly circumscribed holes, 
> >looking as perforations and located on flat bones (skull, sternum, 
> >ribs, ilia) which still contain red marrow in adults). Multiple 
> >myeloma is no 'bone cancer' strictly spoken, it is a neoplastic 
> >disease, in which a clone of plasmocytes (a certain type of white 
> >blood cell that secretes antibodies or immunoglobulins) proliferates; 
> >this causes bone destruction (with the aid of osteoclasts) and  abnormal 
> >secretion of an immunoglobulin (so called 'monoclonal peak') leading 
> >to renal insufficiency and impaired immunity.
 
Gautam Majumdar replied:

> Exactly same lesions can develop if a cancer spreads to the bones. It will be
> virtually impossible to tell from the fossil bone itself which disease (if it 
> was a
> disease) was the cause. Myeloma is a rare disease, metastatic carcinoma
> (spreading cancer) is much more common.

(To prevent confusion: I have not seen the Chasmosaurus skul specimen, nor 
photographs of it; the following reply just applies to multiple 
myeloma (formerly called Kahler's disease) as encountered in humans)

You are right in stating that bone defects (osteolysis) can be caused 
by bone metastases of several types of cancer. Pure osteolysis 
without new formation of bone is especially seen in metastases of 
breast cancer, thyroid cancer, colon cancer and lung cancer. However, 
a radiological picture of multiple adjacent rounded clearly 
circumscribed holes (punched-out lesions, as some perforator was 
applied to the bone) located at the cranium is quite specific (some 
handbooks use the word "pathognomonic") for multiple myeloma. Of 
course it is not sufficient to make the diagnosis, other criteria 
have to be fulfilled (presence of at least 10% pathological plasma 
cells in bone marrow or presence of a definite 'plasmocytoma', 
together with the presence of a lytic bone lesion or the finding of 
an abnormal protein in blood, so called paraprotein, which is a 
immunoglobulin secreted by the pathological plasmacells), which of 
course cannot be examined in a fossil skull.

The punched out lesions are caused by a real destruction of bone by 
osteoclasts, which extends from the trabecular bone (where lies the 
bone marrow) to the cortex. This destruction often caused spontaneous 
fractures.

Myeloma can be experimentally induced in other mammals such as mice 
and dogs: very similar radiological pictures are seen. It would be 
interesting to know if myeloma is described in extant archosaurs as 
birds and crocodiles.

By the way, MM isn't that rare: approximately 1% (in white) and 2% in 
black, of cases of cancer are MM; or 4 to 5 white and 6 to 10 black 
people per 100.000 per year  get this awful disease, for which there 
is yet no cure...

Back to paleontology and sorry for the medical intermezzo,

Pieter Depuydt MD