Systemic Sclerosis (Scleroderma)

Soft tissue at finger tips is decreased and Acro-osteolysis is present.
- There is subtle suggestion of tuftal sclerosis as well.
Amorphous Calcification is present in the forearm, more clearly seen in the detailed view.

Findings are compatible with, but not exclusively diagnostic of, Systemic Sclerosis (Scleroderma).

You may wish to review some facts regarding this entity:

A multi-organ disease (chest, bone, GI, etc.) of unknown etiology, affecting F > M.
- Immune?
- Abnormal collagen metabolism?
- Vascular abnormality?
Clinically,
- Skin thickening (edema ->fibrosis)
- Muscle weakness
- Raynaud's phenomenon -- paroxysmal occlusion of digital arteries.
  - Can be seen as isolated disease of associated with other entities including SLE, RA, dermatomyositis, mixed connective tissue disorder (MCTD).
- Dysphagia
In the hands,
- Atrophy of soft tissue in finger tips
- Soft tissue calcification.
- Acro-osteolysis but DDx is extensive.
  - Scleroderma
  - HPTH
  - Frostbite
  - Leprosy
  - Psoriasis
  - Epidermolysis bullosa
  - Polyvinyl chloride
  - Multicentric reticulohistiocytosis
  - Erosive osteoarthritis
  - Lesch-Nyhan Syndrome
  - Progeria
In joints,
- Extensive involvement of 1st MCP with erosion, Ca, subluxation is characteristic.
- Erosions DIP, PIP must be distinguished from:
  - RA
  - PA
  - Erosive osteoarthritis
Elsewhere,
- metastatic calcification is seen, but must be differentiated from:
  - Hypervitaminosis D
  - Renal Osteodystrophy
  - Milk alkali syndrome
  - Other hypercalcemic states
  - Dystrophic calcification

Ref: Resnick, D., Bone and Joint Imaging, W.B. Saunders, Philadelphia, PA, 1989, pp. 353-360.