Soft tissue
Fibroblastic / myofibroblastic
Superficial acral fibromyxoma
Last author update: 1 April 2013
Last staff update: 27 April 2023 (update in progress)
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PubMed Search: Superficial acral fibromyxoma
Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Clinical features | Prognostic factors | Case reports | Treatment | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Differential diagnosisCite this page: Stuart L. Superficial acral fibromyxoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuesuperficialacral.html. Accessed June 4th, 2023.
Definition / general
- Name is accurate - superficial tumor of fingers and toes with bland fibromyxoid histology
- First described in 2001 (Hum Pathol 2001;32:704)
Terminology
- Also called digital fibromyxoma (Am J Surg Pathol 2012;36:789)
Epidemiology
- Slight male predominance, mean age 5th decade, range 4 - 86 years; about 25% recur (J Cutan Pathol 2008;35:1020, Am J Surg Pathol 2012;36:789)
Sites
- Subungual or periungual region of fingers and toes (Arch Pathol Lab Med 2011;135:1064, Am J Surg Pathol 2012;36:789)
- Also palms, rarely webspaces, heel, ankle (Am J Surg Pathol 2012;36:789)
Clinical features
- Slow growing, solitary mass; often pain (41%, Am J Surg Pathol 2012;36:789)
Prognostic factors
- Local recurrence almost always associated with positive margins
Case reports
- 35 and 45 year old men (Dermatology Online Journal 2008;14:27)
- 53 year old man with tumor of great toe (J Eur Acad Dermatol Venereol 2008;22:255)
Treatment
- Complete excision with routine follow-up (Arch Pathol Lab Med 2011;135:1064)
Gross description
- Well circumscribed, non encapsulated gray-white nodule
- Can be dome shaped, polypoid, verrucous
- Cut surface firm, gelatinous, solid (Arch Pathol Lab Med 2011;135:1064)
Microscopic (histologic) description
- Dermal or subcutaneous tumor composed of bland spindle and stellate cells within a myxoid or collagenous stroma with prominent vessels and mast cells
- Cells are arranged in random, loose storiform and fascicular growth patterns
- Mild nuclear atypia
- Occasional multinuclear stromal cells
- Rare mitotic figures
- Rarely infiltrates bone (Am J Surg Pathol 2012;36:789)
- An epidermal collarette may be present (Dermatol Ther 2020;33:e14517)
Microscopic (histologic) images
Images hosted on other servers:
Tumor at tip of big toe
Spindle cells and mast cells in myxoid matrix (fig1)
CD34+ (fig2)
CD99+ (fig3)
H&E, CD10 and nestin
Positive stains
- CD34 (69%, Am J Surg Pathol 2012;36:789), CD99, vimentin, CD10 (Arch Pathol Lab Med 2011;135:1064)
- Alcian blue (mucinous material, Dermatology 2002;205:285)
- Occasional EMA (7.5%), actin (12%), desmin (6%)
Differential diagnosis
- Acquired digital fibrokeratoma: paucicellular, EMA-, can be CD34- (Arch Pathol Lab Med 2011;135:1064)
- Cutaneous myxoma (superficial angiomyxoma): lobulated pattern; poorly demarcated; may contain an epithelial component, may be associated with Carney complex (Arch Pathol Lab Med 2011;135:1064, Am J Dermatopathol 2004;26:472)
- DFSP: hands and feet are unusual sites, tight storiform pattern at least focally, infiltrative, EMA-
- Fibrous histiocytoma: not well-circumscribed, typically does not involve fingers, palms, or soles, CD34 negative
- Myxoid neurofibroma: no increased vasculature; S100+ (Am J Dermatopathol 2004;26:472)
- Myxoinflammatory fibroblastic sarcoma (inflammatory myxohyaline tumor of distal extremities): virocyte-like and lipoblast-like bizarre cells, prominent inflammation, EMA- (Am J Dermatopathol 2012;34:663)
- Sclerosing perineurioma: cells are arranged in corded, trabecular, and onion-skinned whorling patterns, (Arch Pathol Lab Med 2011;135:1064), usually CD34- (Am J Dermatopathol 2004;26:472); positive for claudin
