Mönckeberg's sclerosis commonly occurs in otherwise healthy elderly patients independently of atherosclerosis. After 35 years of disease, 94% of all diabetic patients present arterial calcification. This is usually an incidental finding during lower limb radiographic examination, although involvement of renal and coronary vessels has been described . The cause of medial calcinosis remains unclear, but some insights into the etiopathogenic process have been provided by isolated studies. Shanahan el al  proposed that a loss of expression of certain proteins related to the inhibition of calcification could be the causative factor. These proteins are Gla protein, osteoprotegerin, fibrillin I and carbonic anhydrase (all produced by vascular smooth muscle cells). Byts et al.  pointed out that medial calcification can be a consequence of various metabolic changes triggered by a necrobiotic injury installed in the vessel wall.
Since its first description in 1903 , MS has only been related to media calcification of small-to-medium-sized arteries, being listed among the primary diseases of the vessels. Calcic involvement of soft tissues has never been described in MS patients. In our case the pharynx involvement was strong enough to produce severe obstructive sleep apnea and the symptoms were clearly associated with the massive tumoral growth of the anterior portion of the neck.
Obstructive sleep apnea results from repetitive episodes of pharyngeal occlusion during sleep which reverse with arousal, thus inducing sleep fragmentation, a low amount of slow wave sleep (stages 3 and 4 non-REM sleep) and a low amount of REM sleep with consequent daytime somnolence . Sleep apnea causes repetitive episodes of hypoxia, hypercapnia and reoxigenation that can lead to a variety of physiological processes including pulmonary hypertension and other vascular consequences. Our patient had a confirmed increase in pulmonary arterial pressure that could not be entired explained by the OSA syndrome. Probably it has been worsened by the concomitant left ventriculat disfunction. The exact cause of the cardiac disfunction could not be widely investigated, but OSA is an important contributor.
Generally, the pathogenesis of upper airway obstruction involves anatomic and neurological components. Obesity, age, male sex, positive family history and alcohol consumption are well known as major risk factors for this disorder in adults. Narrowing may occur at one or more sites in an unstable upper airway due to anatomical partial obstruction as a result of developmental delay, craniofacial abnormalities and neurologic diseases. Our patient was a non-alcoholic, very slim woman (as judged by a body mass index of 17 kg/m2) with no family history of similar disorders.
The massive calcification areas of the pharynx were confirmed by radiological images, laryngoscopic visualization and a biopsy of the exophytic lesion in the pyriform sinus which revealed areas of soft tissue calcification. We excluded metastatic and dystrophic calcification in the light of the histological appearance of the lesion and the absence of malignancy and of rheumatologic or endocrine diseases.
A lower limb X-ray evidenced the classic "rail tracking" appearance of MS described by other authors [1, 4] and a temporal artery biopsy confirmed the intense media calcinosis. The concomitant atherosclerotic process involving the intima layer of the femoral arteries explained the intermittent claudication and weak pulses presented by this patient. Both OSA and MS are recognized as causative factors of atherosclerosis[1, 13]. Additionally, our patient presented low bone mineral density, and this finding supports recent evidences showing association between arterial calcification and osteoporosis[14, 15].
As can be seen in figure 3, the amount of airway obstruction caused by the grossly calcified tissue could be the answer for the discomfort related to CPAP titration. In face of the difficulties related to this approach, tracheostomy was thought to solve this problem. However, the risk of triggering even more tissue calcification secondary to tissue damages discouraged the realization of this procedure.
Alternatively, treatment with intravenous dissodic pamidronate was attempted to stop the phenomenon of calcification and prevent further airway obstruction. This drug has the property to attach to hydroxyapatite crystals preventing both vascular and soft tissue calcification. Additionally, it worked as a treatment for osteoporosis presented by the patient.
Although one can argue about the possible role of upper airway obstruction in intensifying the local deposition of calcium in the soft tissue of the pharynx, the diagnosis of MS was well documented in this case. The present report provides a new insight about this disease, i.e., the fact that the etiopathogenic process involved in the phenomenon of calcification may not be restricted only to the arteries, but may involve the entire organism.