Chemokines & Neovascularization...
What specific role does chemokines play in formation of new vessels by tumour cells? Herbert et al recently (Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0507158102, Dec.2, 2005) demonstrated that chemokines appear to direct the bone marrow progenitor cells into tumour neovessels.

Abstract: Tumor neovasculature substantially derives from sprouting of existing vessels, whereas the functional contribution of bone marrow-derived progenitors to neovessels remains controversial. We used transgenic mouse models of multistep carcinogenesis to monitor incorporation of bone marrow-derived cells into the neovasculature and to elucidate mechanisms of endothelial precursor cell (EPC) recruitment into the tumor microenvironment. We unequivocally demonstrate integration of bone marrow cells into the tumor vasculature as a late event in carcinogenesis that temporally correlates with VEGF release by the tumor and mobilization of circulating EPC in the periphery. Moreover, we demonstrate a chemokine-dependent mechanism of EPC homing into tumor, whereby neovessels of late-stage tumors release a battery of CC chemokines, which direct CCR2⁺ and CCR5⁺ progenitors into the vasculature. Thus, we show that tumor vessels promote their own growth and development in a self-amplifying fashion.
 

New Forum For Otolaryngologists in Africa...
A new online forum has just being created to enable Otolaryngologists in Africa share opinions, discuss cases, and keep abreast of other global events concerning the sciences and arts of otolaryngology. You are cordially invited to be a member of this new group designed to advance otolaryngology to the NEXT level. Feel free to forward this information to other Otolaryngologists known to you who might be interested in being part of this event. To view this blogsite, click Here...

What tumour is this.....?
What progressively expanding temporal bone lesion producing copious amount of keratin aggressively extend into surrounding bone, soft tissue and intracranial? Cholesteatoma? Now hold your breadth! What if the only finding at histology was normal squamous epithelial basal cell layer with remarkable acanthosis and extensive hyperkeratosis? Manni, Pauwells & Creytens recently (ORL 2005;67:363-368) reported this finding in 2 patients and believed it is a new disease entity.

Abstract: Two patients with a highly destructive histologic nondysplastic squamous epithelial lesion of the temporal bone are described. Both tumors were characterized by the production of copious amounts of keratin material which progressively extended in the temporal bone, surrounding bony structures, soft tissue and intracranially, with concomitant functional disorders. Only small amounts of epithelial cells were found. CT scanning revealed extensive and progressive destruction of the temporal bone, skull base in both patients, clivus and arch of atlas in one patient, besides intracranial and intracerebellar abscess formation. Despite extensive surgical therapy, the disorder was unmanageable. Histology showed a normal squamous epithelial basal cell layer with remarkable acanthosis and extensive hyperkeratosis. Material obtained at autopsy demonstrated intracerebellar extension of keratin material in one patient and in the hemicerebellectomy specimen of the other patient. To our knowledge, this disease entity has not been reported before.

 

What is the diagnosis?

Parting Shot...
If you have an interesting case to discuss or share with other Otolaryngologists all over Africa, feel free to email me or at best go to otolaryngology in Africa blogsite and post your case

Also, if you are among those who requested for a copy of DODA at the last ORLSON Meeting @ Port Harcourt, please take time to view the DODA - FAQ page, and expect your copy of the program soon

Till Next Week,

Biodun