A 50-year-old man comes to the office for evaluation of a nodule in his palm just proximal to the third metacarpophalangeal joint. It has grown larger since it first appeared several months ago and he now has mild flexion of the finger, which he is unable to straighten. The patient reports that his mother had similar problems with her fingers. Examination of the affected hand is shown in the exhibit. Which of the following pathologic processes is most likely involved in this patient's condition?
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This patient has Dupuytren contracture (DC), a condition caused by progressive fibrosis of the superficial palmar fascia. The disease typically involves the fascia at the base of the middle, ring, and little fingers. Although the etiology of DC is unknown, risk factors include age >50, male sex, family history, and Northern European ancestry.
DC is thought to be caused by overstimulation of the Wnt-signaling pathway, which helps regulate cellular proliferation, polarity, and differentiation. Initial findings include painless fascial thickening with puckering of the skin just proximal to the affected metacarpophalangeal joint(s).
As fibrosis continues, pathognomonic fascial nodules form along the flexor tendons composed of proliferating fibroblasts and disordered type III collagen. The nodules eventually coalesce into palpable fibrotic cords that tether the flexor tendon to the palmar fascia, leading to loss of finger extension (ie, contractures) at the metacarpophalangeal and proximal interphalangeal joints.
(Choice B) Heterotopic bone formation in muscles is characteristic of myositis ossificans, a benign condition that typically develops after contusion to large muscle groups (eg, quadriceps femoris). Patients often have pain in the affected muscle and a deep, palpable lump (ie, heterotopic bone).
(Choice C) Linear deposits of calcium hydroxyapatite in the periarticular structures cause a painful inflammatory condition called calcific peritendinitis. However, it usually affects the rotator cuff; hand and wrist involvement is uncommon and would present with associated inflammatory changes (eg, redness, swelling, warmth).
(Choice D) Mucinous, gelatinous fluid filling of the tendon sheath is characteristic of a ganglion cyst. Unlike fibrotic nodules in DC, ganglion cysts present as large, mobile, rubbery nodules that do not lead to contractures of the hand.
(Choice E) Neutrophilic infiltration of tendon sheaths is characteristic of bacterial tenosynovitis. Because it is an inflammatory condition, it presents with significant redness, warmth, and swelling, none of which are present in DC.
Educational objective:
Dupuytren contracture is caused by progressive fibrosis of the superficial palmar fascia due to excessive fibroblast proliferation. Pathognomonic fibrotic nodules and cords form along the flexor tendons, limiting extension of the affected digits.