PMC5241456_01
AP (a) and lateral (b) radiographic imaging of distal femur demonstrates aberrant calcification of the suprapatellar region within the soft tissue. Transverse (c) and lateral magnetic resonance imaging (d) reveals that the calcified mass is confined to the subcutaneous tissue with no connections to the underlying bone.
CRIOR2017-8672816.001.jpg
PMC5241456_01_CRIOR2017-8672816.001.jpg
fig1
Plain radiographs showed an oval, calcified mass within the soft tissue of the suprapatellar region (Figures 1(a) and 1(b)). Magnetic resonance imagining revealed a mass confined to the subcutaneous soft tissues along the anteromedial aspect of the thigh superficial to the vastus medialis causing extrinsic mass-effect without deep invasion (Figures 1(c) and 1(d)).
Intraoperative imagining demonstrates the mass within the subcutaneous tissue in the anteromedial region of the distal femur (a). An elliptical incision was made (b) and the calcified mass was carefully dissected and removed (c).
CRIOR2017-8672816.002.jpg
PMC5241456_01_CRIOR2017-8672816.002.jpg
fig2
For the excision biopsy, an elliptical incision was made surrounding the nonadhesive area of the skin in Langer's lines (Figure 2).
Safranin-O (25x) demonstrates cartilage cap with endochondral bone formation underlying the dermis. Zone of proliferation, hypertrophy, and apoptosis with new bone formation are identified at 100x. These findings are consistent with osteochondroma.
CRIOR2017-8672816.003.jpg
PMC5241456_01_CRIOR2017-8672816.003.jpg
fig3
The sections demonstrated a nodular, slightly disorganized cartilaginous cap surrounding the lesion that progressed to endochondral-like bone formation (Figures 3 and 4).
Safranin-O staining (25x) demonstrates calcified chondrocytes located just deep to the dermal area of the tissue (red). Masson's Trichrome (25x) demonstrates the epidermal (red) and dermal (blue) layer that is directly adjacent to the chondrocytic area. H&E and Masson's Trichrome (25x) demonstrate endochondral bone formation adjacent to a cartilaginous cap indicating the formation of an osteochondroma.
CRIOR2017-8672816.004.jpg
PMC5241456_01_CRIOR2017-8672816.004.jpg
fig4
The sections demonstrated a nodular, slightly disorganized cartilaginous cap surrounding the lesion that progressed to endochondral-like bone formation (Figures 3 and 4).