idiopathic osteolysis is a heterogeneous group of rare diseases in which there is a spontaneous , aggressive and extensive bone resorption .
idiopathic osteolysis was first described in 1838 and again in 1872 by jackson ( 1 , 2 ) who reported a case of " boneless arm " . in 1955 ,
gorham and stout ( 3 ) defined a specific disease entity and reviewed 24 cases from the literature .
the gorham - stout syndrome presents progressive idiopathic osteolysis of one bone or contiguous bones around one focus , without respect for joint boundaries . in 1985 ,
there have been a number of publications and case reports which do not appropriately fit into this classification ( 8 - 13 ) .
we present a case of histologically proven massive osteolysis documented with plain radiography , ct and mri . to our knowledge , this is the first case in which multifocal , non - contiguous , osteolytic skip lesions without associated nephropathy and without a hereditary pattern is described in one extremity .
a 38-year - old man is initially presented with pain and decreased strength in the left arm .
laboratory results were normal including renal function tests ( urea , creatinine ) , thyroid and parathyroid hormone ( pth ) tests .
the patient was treated with non - steroidal anti - inflammatory drugs but the pain was not relieved , the patient was referred for radiography 2 years later . during this time , radiography demonstrated almost complete non - contiguous osteolysis in the left elbow , proximal and distal radius , ulna , wrist , carpal bones , proximal and distal metacarpals and phalanges ( fig .
static images from bone scintigraphy with 99 technecium methylene diphosphate ( 99mtc - mdp ) showed increased activities in the osteolysed regions ( fig .
1e , f ) . to define the extent of the osteolysis , ct examination was performed .
mri demonstrated that the soft tissue masses and the affected bones were hypointense to isointense with muscle on t1-weighted imaging ( tr / te , 732/12 ) and were of heterogeneous signal intensity on t2-weighted imaging ( tr / te , 3986/99 ) ( fig .
multi - site fine needle aspiration biopsy and tru - cut biopsy were undertaken ; bone specimens were taken from proximal , distal radius and proximal ulna for pathological examinations .
this revealed fibrous tissue containing proliferated vascular structures replaced with bone trabeculae and bone marrow ( fig .
the pathological specimen obtained at open biopsy of a lesion in the left proximal radius also confirmed such findings .
gorham disease must be distinguished from osteolysis secondary to other pathologic processes , including the hereditary , metabolic , neoplastic , infectious and immunologic etiologies .
common differential diagnoses included hereditary multicentric osteolysis , essential osteolysis with nephropathy , metastasis , osteomyelitis , and rheumatoid arthritis .
the clinical findings are usually helpful when ruling out these diseases ( 5 , 6 ) .
idiopathic osteolysis is a heterogeneous group of rare diseases in which there is spontaneous onset of mostly peripheral osteolysis without obvious reasons .
( 4 ) described the most commonly accepted classification with five types of idiopathic osteolysis .
type i , hereditary multicentric osteolysis with dominant transmission is commonly seen at early childhood with complaints of spontaneous pain and swelling beginning in the hands and feet .
type ii , hereditary multicentric osteolysis with recessive transmission is similar to type i except for possible associations with severe generalized osteoporosis .
type iii , is a non - hereditary multicentric osteolysis with nephropathy appearing in childhood .
type iv , gorham - stout syndrome is a monocentric syndrome which involve any part of the skeleton .
rarely , two or more anatomic regions are affected , separated by normal osseous structures .
apparently , any bone can be involved , including the small tubular bones of hands and feet , spine , skull and the mandible .
the gorham - stout syndrome presents as progressive idiopathic osteolysis of one bone or contiguous bones around one focus without respect for joint boundaries . while contiguous bony involvement is typical , multiple foci with skip lesions have not been reported in the literature ( 14 ) .
type v , winchester syndrome is a rare childhood carpotarsal osteolysis syndrome with autosomal recessive transmission .
it is associated with contractures , shortness of stature , skin lesions , corneal clouding and osteoporosis without nephropathy .
this patient , without any underlying conditions , was diagnosed as idiopathic osteolysis based on radiologic , morphological and clinical findings .
however , our case does not readily fit in to the classification of idiopathic osteolysis according to hardegger et al .
this case fits most closely into the type iv of hardegger classification , however multifocal , non - contiguous osteolysis with skip lesions differ from the usual characteristics of gorham syndrome .
there have been increasing numbers of cases which can not accurately be placed within this classification ( 8 - 13 ) .
white ( 8) reported four patients with multifocal osteolysis in association with severe skin lesions .
beals and bird ( 9 ) observed one case of carpotarsal osteolysis without associated nephropathy and a hereditary pattern .
( 10 ) described a woman with osteolytic lesions of the metacarpal and metatarsal bones and terminal phalanges without a family history or renal involvement ; burkhard et al . ( 13 ) and tauro ( 11 ) noted cases of ' multicentric gorham - stout syndrome ' and downing et al . ( 12 ) published one case of multicentric osteolysis in both hands and feet , especially of the phalanges , associated with normal renal functions and with no genetic basis .
we report a unique pattern of involvement in the upper left extremity with non - contiguous , multifocal osteolysis .
this case is an addition to the enlarging group which can not be readily placed in the proposed classification of idiopathic osteolysis .
 a patient with a 2-year history of pain in the left arm , and decreased strengths unrelieved by non - steroidal anti - inflammatory therapy , was being referred for repeating radiography . 
 the radiologic examinations have demonstrated a unique pattern of non - contiguous osteolysis in the left elbow , proximal and distal radius , ulna , wrist , carpal bones , proximal and distal metacarpals and phalanges . 
 multi - site biopsies were being performed and confirmed the diagnosis of massive osteolysis . to our knowledge , this is the first case in which multifocal , non - contiguous osteolysis with skip lesions without associated nephropathy and without a hereditary pattern is being described in one extremity . 
INTRODUCTION
CASE REPORT
DISCUSSION