Low-Grade Central Osteosarcoma: A Difficult Condition to Diagnose

Table 1

Patients within the case series.

Gender	Age at diagnosis	Site	Primary or secondary referral	Previous diagnosis	Previous treatment	Definitive treatment	Chemotherapy	Followup (months)	Outcome
M	11	Mid tibia	Secondary	Osteoma	Excision “osteoma,” recurred after 1 year	Resection and fibula graft		186	No evident disease
F	14	Distal femur	Primary		None	EPR	Thought to be high grade	48	No evident disease
M	18	Distal femur	Secondary	Mesenchymoma	Curettage, LR after 4 yrs, recuretted, further LR 3yrs	EPR	90	No evident disease
M	19	Distal femur	Secondary	Cyst	Curettage and bone graft of fracture through cyst, LR 9 months	EPR	170	No evident disease
F	19	Distal femur	Secondary	Desmoplastic fibroma	Curettage and fixation of fracture through cyst, LR 3 yrs, recuretted and bone grafted, slowly progressive lesion for 4 years	EPR	24	No evident disease
M	29	Proximal femur	Primary	Atypical fibrous dysplasia	Curettage, then curettage and bone graft	EPR	As higher grade on LR	4	No evident disease
M	32	Distal femur	Secondary	Cyst	Curettage of cyst, uncertain diagnosis, post op RT, recurrence after 7 yrs as high grade tumour, lung met	EPR and thoracotomy	As higher grade on LR	7	No evident disease
F	33	Ilium	Primary		None	Excision		10	No evident disease
M	37	Proximal humerus	Secondary	Giant cell tumour	Curettage, LR 9 months with high-grade areas	EPR	As higher grade on LR	212	No evident disease
F	38	Ilium	Primary	Atypical fibrous dysplasia	Biopsy x3	Resection and fibula graft	As higher grade on LR	57	LR 14 months, high grade, chemo and amputation, alive with metastases
F	43	Distal femur	Primary		None	EPR		64	No evident disease
F	45	Proximal tibia	Primary	MFH	None	EPR	As initially thought be MFH	109	LR and metastatic disease at 102 months died 109 months
F	47	Distal femur	Primary	Fibroosseous lesion	Biopsy x2, curettage and cementation	EPR	Thought to be high grade after curettage	16	No evident disease
M	48	Calcaneum	Primary		None	Amputation	60	No evident disease
M	51	Distal femur	Primary		None	EPR	156	No evident disease
F	54	Distal femur	Primary		None	EPR	171	No evident disease
M	55	Proximal tibia	Primary	Fibrous dysplasia	Biopsy suggested fibrous dysplasia, curettage led to diagnosis	EPR	144	No evident disease
F	72	Proximal tibia	Secondary	Cyst? malignant	Curettage and bone graft of cyst, recurred 40 yrs later as LGCO	EPR	52	No evident disease

Key: RT: radiotherapy, CT: chemotherapy, LR: local recurrence, EPR: endoprosthesis, MFH: malignant fibrous histiocytoma, LGCO: low-grade central osteosarcoma.