Intradermal proliferative fasciitis on the finger.

Area of Science:

• Dermatopathology
• Soft Tissue Tumors

Background:

• Intradermal nodular fasciitis is a rare finding, with about 100 cases reported since 1990.
• Intradermal proliferative fasciitis is exceptionally rare, with only two prior cases documented, both in the postauricular area.

Observation:

• This report presents the third documented case of intradermal proliferative fasciitis.
• The case is unique as it is the first occurrence reported on a finger.
• This specific case exhibited unusually slow growth over time.

Findings:

• The tumor showed a complete lack of smooth muscle actin expression.
• This absence of smooth muscle actin expression has been previously reported in only one other case.

Implications:

• This case expands the known anatomical locations for intradermal proliferative fasciitis.
• The distinct presentation may aid in future diagnoses of this rare condition.
• Further research into the cellular mechanisms of this variant of fasciitis is warranted.