MRI has characteristic features distinguishing PVNS, mainly the presence of hemosiderin
deposition, especially through gradient-echo pulse.
(c) Corresponding susceptibility-weighted image demonstrates ill-defined areas of hemosiderin
deposition in the left fronto parietal region representing areas of hemorrhage.
As the injury evolves, red blood cell lysis and hematoma resolution occur with hemosiderin
The lesions tend to bleed, causing hemosiderin
deposition and characteristic low signal intensity with all pulse sequences.
Stroma was vascular and made up of numerous dilated blood vessels; a large thrombus was noted in the centre with hemosiderin
pigmentation (Figure 2b).
Histologically, PVNS reveals a hypertrophic synovial process that is characterized by villous, nodular, or villonodular proliferation and hemosiderin
Caption: Figure 3: (a) Plenty of endometrial gland and stroma (x10), (b) hemosiderin
laden of macrophages (x10)
Shows fibrous stroma with numerous hemosiderin
Dermis shows villous hair follicle with sebaceous gland hyperplasia with peri-infundibular infiltrate of lymphocytes and plasma cells with dilated capillaries and extravasation of hemosiderin
Pseudomelanosis occurs due to deposition of pigments like iron or hemosiderin
in the histiocytes.
Otherwise, hemorrhagic alterations and hemosiderin
pigment were present (Figure 3).