Case Report #0648
Submitted by: Susanna Spence, M.D.
Faculty reviewer: Manickam Kumaravel, M.D
Date accepted: 11 January 2010
Radiological Category: Principal Modality (1):
Principal Modality (2):
This case report presented at noon conference, Case-Based Radiology-Pathology
Correlation, July 2009.
MRI, nuclear medicine
20 year old male with left forearm pain for 3 months.
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There is an ill-defined lesion with a wide zone of transition centered at the metaphysis
of the distal ulna with surrounding new bone formation and periosteal reaction. There
is increased tracer uptake on the bone scan images. There is no evidence of additional
lesions on the bone scan (mild uptake at the left hindfoot was found to be due to tarsal
coalition). MR images demonstrate low signal intensity consistent with the areas of
ossification, and surrounding edema. There are patchy areas of contrast enhancement.
Findings and Differentials
Age (y) Possible Diagnoses
1–30 Ewing sarcoma, osteogenic sarcoma
30–40 Giant cell tumor, parosteal sarcoma, fibrosarcoma,
malignant fibrous histiocytoma, 1° lymphoma of bone
Over 40 Chondrosarcoma, metastatic disease, myeloma
The most likely histologic diagnosis for a given bone lesion can be broken down by
its imaging appearance and the patient’s age.
In this case, the lesion has aggressive features, with a wide-zone of transition,
cortical breakthrough and a soft tissue component, favoring a malignant
In this 20 year old patient, the most likely diagnoses would be either Ewing
sarcoma or osteogenic osteosarcoma (these diagnoses will be discussed
• Most common primary malignant tumor of bone in
adolescents and young adults.
• Intramedullary (high grade, telangiectatic, low
grade, small cell, osteosarcomatosis, and gnathic),
• Surface (intracortical, parosteal, periosteal, and
• Extraskeletal (rare).
Osteosarcoma may also occur as a secondary lesion in
association with underlying benign conditions (e.g.
Paget’s, fibrous dysplasia, previous radiation)
Murphey et al. The many faces of osteosarcoma. RadioGraphics
1997; 17: 1205-1231.
•Male: female ratio 1.5-2:1
•White > black
•Most commonly presents around the knee, with the distal femur (40-
45%) and proximal tibia (16-20%) being the most common sites.
•Most common type is intramedullary, which occurs most commonly
within the metaphysis (90-95%)
•Majority (~90%) demonstrate “fluffy” or “cloud-like” areas
characteristic of osteoid formation
•Tends to violate the cortex without altering osseous contours
•May occasionally be primarily lytic
•Associated with aggressive periosteal reaction, which may be
lamellated, sunburst, or feature a Codman’s triangle (*).
In this case:
The appearance of the lesion, with fluffy surrounding new bone
formation, periosteal reaction and violation of the cortex without
alteration in osseous contours, along with the age of the patient,
all strongly favor osteogenic osteosarcoma as the primary
The patient went on the biopsy (shown below). Low power and high power views
demonstrate pleomorphic, atypical cells are shown producing areas of pink
osteoid, consistent with osteogenic osteosarcoma.
•10% or all primary bone tumors
•Male: female ratio 2:1
•95% between ages 4 and 25
•95% in whites
•Most common locations: pelvis, humerus, femur, distal
•Average time to diagnosis: 6 months
•~59% metadiaphyseal, 35% diaphyseal
•Permeative lesion located in the medullary cavity
•Aggressive periosteal reaction, may be amorphous, sunburst
•Often associated with a large soft tissue mass
Reinus WR, Gilula LA, IESS Committee. Radiology of
Ewing Sarcoma: Intergroup Ewing’s Sarcoma Study
(IESS). RadioGraphics 1984; 4 (6): 929-944.
In this case:
The prominent finding of new bone formation, along
with the cortical breakthrough without disturbance of
the osseous contours, is typical of osteogenic
osteosarcoma. While some periosteal reaction was
present in our case, it is often a very much more
prominent feature of Ewing’s sarcoma. Therefore,
Ewing’s sarcoma is not the favored diagnosis in this
Reinus WR, Gilula LA, IESS Committee. Radiology of Ewing’s Sarcoma
:Intergroup Ewing’s Sarcoma Study (IESS). RadioGraphics 1984; 4 (6): 929-944.