Fibroepithelial Polyp

Slide 1 · Fibroepithelial Polyp

Acrochordon • skin tag

Clinical morphology | histopathology | differential diagnosis

Dr Abu Suraih Sakhri

MBBS, MD (Pathology)

www.abusuraihsakhri.com

Slide 2 · Learning outcomes

Recognize the typical soft, pedunculated cutaneous lesion and its clinical distribution.

Explain the fibrovascular core and benign epithelial covering on histology.

Distinguish common mimics and identify when biopsy or specialist review is appropriate.

Interpret metabolic associations and rare syndromic clues without overdiagnosis.

Slide 3 · Place in the skin pathology curriculum

A common benign exophytic cutaneous lesion in the benign epithelial-tumor chapter.

The central diagnostic task is lesion recognition, not cancer staging or grading.

Morphology, clinical context and differential diagnosis determine management.

Slide 4 · Terminology: One entity, several labels

Fibroepithelial polyp, acrochordon and skin tag refer to the usual cutaneous lesion.

Other descriptive terms include soft fibroma or cutaneous tag.

“Squamous papilloma” may be used broadly; Site and histology must resolve ambiguity.

Slide 5 · The diagnostic definition

Appearance

Soft, benign, exophytic skin growth

Attachment

Often on a narrow pedicle

Core

Fibrovascular connective tissue

Covering

Benign squamous epithelium

Slide 6 · Benignity is a histologic statement

Conventional acrochordons lack invasive malignant architecture.

The surface squamous epithelium is cytologically benign.

An atypical or changing polypoid lesion should not be assumed to be an acrochordon.

Slide 7 · Anatomical distribution

Common sites include the neck, trunk, face and intertriginous regions.

Axillae and groin are typical high-friction sites.

Eyelids and other skin folds may be involved; Localization alone is not diagnostic.

Slide 8 · Age pattern

Usually becomes clinically apparent in middle-aged or older adults.

Number and prominence may increase over time.

Skin tags can occur in younger patients; Unusual age increases the value of context.

Slide 9 · Three recognized clinical forms

Small papule

Tiny soft outgrowth in a skin fold

Filiform

Narrow thread-like process

Pedunculated

Broader soft head on a stalk

Slide 10 · Macroscopic consistency

Typical lesion is soft and compressible rather than fixed or indurated.

A “bag-like” appearance reflects the soft connective-tissue core.

Firmness, ulceration or persistent spontaneous bleeding may merit closer evaluation.

Slide 11 · Surface coloration

Commonly skin-colored or mildly hyperpigmented.

Lesions may be paler or darker than adjacent skin.

Color alone cannot exclude a melanocytic or malignant polypoid lesion.

Slide 12 · Anatomy of a stalked skin tag

1. Benign squamous covering

Outer layer of non-atypical stratified squamous epithelium.

2. Fibrovascular head

Loose collagen and small blood vessels in the polyp.

3. Narrow pedicle

Constricted junction; Susceptible to twisting and ischemia.

4. Surrounding native skin

Underlying epidermis and dermis at the point of origin.

Pedicle

Native skin

Original schematic

Slide 13 · A narrow pedicle matters

The stalk distinguishes a typical pedunculated tag from many broad-based papules.

A small connecting stalk can become twisted or traumatically stretched.

Pedunculation supports—but never proves—the clinical diagnosis.

Slide 14 · Solitary versus multiple lesions

Some patients present with a single troublesome lesion.

Others have clusters in neck or axillary folds.

Distribution and number guide history-taking, not a diagnosis of an underlying syndrome.

Slide 15 · Why an otherwise harmless lesion is noticed

Friction with clothing or jewellery can produce irritation.

Location may create cosmetic concern or repetitive snagging.

New pain or color change often relates to mechanical injury, but requires examination.

Slide 16 · Symptoms: Uncomplicated versus complicated

Uncomplicated acrochordons are often asymptomatic.

Recurrent friction may cause focal discomfort, itching or minor bleeding.

Sudden tenderness and dark discoloration suggest possible vascular compromise.

Slide 17 · Torsion can lead to ischemic injury

Pedunculated lesion

Twist or traction at stalk

Compromised microvascular flow

Congestion, infarction and pain

Slide 18 · Torsion is a recognized source of pain

Ischemic necrosis after pedicle torsion.

An infarcted tag may darken and be acutely tender.

A black, bleeding or rapidly changing polyp still needs clinical differential assessment.

Slide 19 · Clinically concerning departures

Persistent spontaneous bleeding, atypical pigment or irregular growth pattern.

A broad firm base, fixation or surface ulceration unexplained by trauma.

History or examination inconsistent with an otherwise ordinary skin tag.

Slide 20 · What lies beneath the surface?

Benign epithelial envelope

Loose collagen and connective tissue

Small-caliber blood vessels

No infiltrating tumor front

Squamous epithelium

Fibrovascular stroma

Original schematic — not an H&E micrograph

Slide 21 · Microscopy: Low-power architecture

Well-circumscribed polypoid exophytic configuration.

Stromal core is continuous with the underlying superficial dermis.

The surface is covered by benign stratified squamous epithelium.

Slide 22 · Microscopy: The epithelial covering

Squamous epithelium can be flattened, thickened or papillomatous.

Keratinization may vary with local friction and site.

Marked atypia is not a defining feature of ordinary acrochordon.

Slide 23 · Microscopy: Stromal collagen

Loosely arranged collagen predominates in the central core.

The stroma is often relatively hypocellular.

Loose collagen helps explain the soft, flexible gross texture.

Slide 24 · Microscopy: Vascular component

Small vessels traverse the connective-tissue core.

Vascularized stroma underlies the epithelial surface.

Mechanical twisting of the stalk can compromise these vessels.

Slide 25 · Microscopy: Epidermis versus appendages

The key surface feature is benign squamous epithelial coverage.

Typical lesions do not require a proliferating adnexal tumor component.

Follicular epithelial strands suggest a different lesion, particularly fibrofolliculoma.

Slide 26 · Gross-to-microscopic correspondence

Soft head

Loose stromal collagen

Slender stalk

Restricted attachment to dermis

Skin-coloured surface

Benign squamous lining

Pain after twisting

Possible stromal ischemia

Slide 27 · A lesion is not diagnosed by “fibrous” alone

The fibrovascular core must be interpreted with the architecture of its covering.

Bland collagenous stroma also occurs in other polypoid skin lesions.

Examine the entire clinical–histological pattern before issuing a diagnosis.

Slide 28 · Infarction on histology: Interpretation

If torsion occurs, necrosis and secondary inflammation may obscure the usual pattern.

A traumatized lesion can become dark, tender or hemorrhagic.

Adequate sampling is important if the viable lesion remains diagnostically uncertain.

Slide 29 · What histology does not usually require

No molecular test is routine for a clinically and histologically typical skin tag.

No formal tumor grade or stage is assigned to an uncomplicated benign lesion.

Immunohistochemistry is not a substitute for recognition of ordinary architecture.

Slide 30 · Practical dermatopathology reporting

Site / clinical history

Document when supplied

Architecture

Polypoid skin with benign covering

Stroma

Loose fibrovascular connective tissue

Conclusion

Fibroepithelial polyp (acrochordon)

Slide 31 · Pathogenesis: Knowns and unknowns

The fundamental cause of sporadic skin tags remains incompletely established.

Mechanical, metabolic and hormonal factors are proposed contributors.

An observed association must not be treated as proof of a single causal pathway.

Slide 32 · Proposed contributing contexts

Local factors

Skin-fold friction / irritation

Host factors

Age, adiposity, insulin resistance

Hormonal milieu

Pregnancy-related prominence

Slide 33 · Friction: Plausible, not exclusive

Tags concentrate in areas where skin surfaces rub.

Repeated chafing is a plausible local growth-promoting influence.

Friction does not explain every site or individual lesion.

Slide 34 · Age and tissue mechanics

Acrochordons are more commonly encountered with advancing age.

Age-related local dermal change has been proposed as a permissive factor.

The precise sequence from altered dermal support to polyp formation is uncertain.

Slide 35 · Pregnancy-related prominence

Increasing number or prominence during pregnancy.

Hormonal stimulation is a suggested explanation rather than a proven mechanism.

The finding is not, by itself, a pathologic pregnancy marker.

Slide 36 · Obesity: Epidemiologic association

Skin tags are more numerous in some patients with obesity.

Fold distribution and metabolic factors may both contribute.

No skin tag count provides a validated diagnosis of obesity or metabolic disease.

Slide 37 · Type 2 diabetes and insulin resistance

Acrochordons are associated with diabetes and insulin resistance in observational studies.

This is a risk association, not a diagnostic criterion for diabetes.

Assess cardiometabolic risk using established clinical standards.

Slide 38 · Acanthosis nigricans: A related examination clue

Velvety hyperpigmented plaques in flexures may coexist with skin tags.

The concurrent pattern may increase suspicion of insulin resistance.

Acanthosis nigricans and acrochordons are distinct morphologic processes.

Slide 39 · Association is not equivalent to screening indication

('Skin tags', 'A cutaneous observation')

('Metabolic risk', 'Interpret age, BMI, history, other findings')

('Assessment', 'Follow risk-based clinical practice')

Slide 40 · Intestinal polyposis: Interpret cautiously

Robbins mentions an occasional association with intestinal polyposis.

Ordinary skin tags alone do not establish a polyposis syndrome.

Use standard colorectal screening indications unless other clinical clues exist.

Slide 41 · Viral causation remains uncertain

HPV DNA has been reported in some studies of skin tags.

Detection does not establish that HPV causes typical acrochordons.

The viral wart differential still matters because warts have different morphology.

Slide 42 · Birt–Hogg–Dubé syndrome: Relevant but rare

Occasional co-occurrence with perifollicular mesenchymal tumors.

Sporadic acrochordons are very common and nonspecific.

Genetic concern is driven by fibrofolliculomas and associated systemic findings.

Slide 43 · Birt–Hogg–Dubé: Distinguish the lesions

Feature

Acrochordon

Fibrofolliculoma

Clinical configuration

Soft, often stalked

Small, dome-shaped papule

Usual pathology

Fibrovascular core

Follicular epithelial strands in fibrous stroma

Syndromic value

Low specificity

Much greater diagnostic relevance

Slide 44 · When a syndrome work-up becomes reasonable

Multiple facial fibrofolliculoma-like papules and compatible family history.

History of spontaneous pneumothorax or characteristic lung cysts.

Renal tumors with compatible features warrant genetics-guided evaluation.

Slide 45 · BHD mechanism is not skin-tag pathogenesis

Pathogenic FLCN variants underlie Birt–Hogg–Dubé syndrome.

That molecular association does not make ordinary skin tags a germline test indication.

Do not label sporadic acrochordons as “BHD lesions” without supporting context.

Slide 46 · Differential diagnosis: Bedside distinctions

Mimic

Features raising alternative

Key distinction

Verruca

Rough keratotic surface

HPV-related epithelial proliferation

Seborrheic keratosis

Waxy, stuck-on plaque

Basaloid epidermal proliferation

Melanocytic nevus

Pigmentation / melanocytic pattern

Nevomelanocytic cells

Slide 47 · Common wart versus skin tag

Warts often have a rough or keratotic surface.

They are HPV-related epidermal proliferations, unlike a typical soft stromal tag.

A filiform wart can look stalked; Examine surface texture and clinical context.

Slide 48 · Seborrheic keratosis versus skin tag

Seborrheic keratoses often have a waxy, “stuck-on” surface.

Their hallmark histology differs: Basaloid proliferation with horn cysts.

A pedunculated variant can cause clinical ambiguity.

Slide 49 · Melanocytic nevus versus skin tag

Some melanocytic nevi are intradermal and pedunculated.

Pigment or dermoscopic melanocytic features may be informative.

Histology demonstrates melanocytic nests/cells rather than only a fibrovascular core.

Slide 50 · Neurofibroma versus skin tag

Soft neurofibromas may resemble skin tags clinically.

A neural spindle-cell proliferation distinguishes neurofibroma microscopically.

Numerous neurofibromas require a different systemic assessment.

Slide 51 · Basal cell carcinoma can be polypoid

Rare BCC variants can mimic benign exophytic papules.

Bleeding, persistent ulceration or clinical atypia warrants tissue diagnosis.

Microscopic infiltrative/basaloid tumor architecture differs from an acrochordon.

Slide 52 · Polypoid melanoma: Avoid diagnostic anchoring

Pigmented or amelanotic melanoma may form a raised or pedunculated nodule.

Evolution, atypical appearance, ulceration or suspicious dermoscopy changes the pathway.

Do not destroy an uncertain lesion without appropriate assessment.

Slide 53 · A focused morphology comparison

Characteristic

Acrochordon

Needs differential

Attachment

Often narrow stalk

Broad / irregular / fixed base

Texture

Soft and pliable

Firm, verrucous or ulcerated

History

Long-standing / friction symptoms

Unexplained rapid change or bleeding

Pathology

Bland squamous + fibrovascular core

Atypical cellular or architectural features

Slide 54 · Anogenital lesions need contextual diagnosis

Vulvar and perianal skin tags are often benign.

Site-specific mimics include condyloma and reactive/inflammatory tags.

Atypia, ulceration or substantial growth may justify biopsy and a broader differential.

Slide 55 · Clinical evaluation in four steps

History: Duration and evolution

Exam: Stalk, texture, pigment, distribution

Look for trauma and relevant risk factors

If atypical: Biopsy / specialist assessment

Slide 56 · When clinical diagnosis is sufficient

Classic small, soft, pedunculated lesion in a usual location.

Stable course, nonconcerning surface and no discordant history.

The clinician may diagnose without histology when confident and appropriate.

Slide 57 · When to obtain histopathology

Unexpectedly large, atypical, ulcerated, irregularly pigmented or changing lesion.

Clinical uncertainty between tag and neoplasm.

Excised tissue should be submitted according to local pathology policy and judgment.

Slide 58 · Specimen orientation and sampling

Record anatomic site, size and clinical concern when provided.

Examine the head and attachment, especially if there is an unusual solid base.

Any suspicious focus should be represented adequately in sections.

Slide 59 · Management decision pathway

Typical and asymptomatic → reassurance

Symptomatic or cosmetic concern → removal option

Atypical or uncertain → diagnostic assessment

Systemic risk → evaluate independently

Slide 60 · Removal by simple excision

Clinician-performed snip or shave excision is a common option.

Local anesthesia and hemostasis are chosen according to size and site.

Removal addresses the individual lesion; New skin tags can arise later.

Slide 61 · Other accepted removal methods

Cryotherapy, electrosurgery and ligation are described options.

Choice depends on lesion size, location, patient preference and local expertise.

When diagnostic uncertainty exists, preserve tissue for pathology rather than destroy it.

Slide 62 · Potential procedural complications

Bleeding and local pain are the principal immediate considerations.

Scarring, dyschromia or infection can occur after removal.

Unsupervised home excision risks injury and missed diagnosis.

Slide 63 · Patient counselling: Precise reassurance

A typical acrochordon is benign and does not require treatment.

Removing one lesion does not eliminate a tendency to form others.

Seek review for new atypical growth, persistent bleeding or unexplained change.

Slide 64 · Case 1 — a typical neck lesion

A 53-year-old presents with several soft skin-coloured outgrowths along the lower neck, intermittently catching on a collar.

Most likely diagnosis and next step?

Pedunculated

Soft

Long-standing

No suspicious evolution

Slide 65 · Case 2 — sudden pain and blackening

A long-standing narrow-stalked axillary tag becomes painful and dusky after repeatedly snagging on clothing.

What explains the acute change, and what must not be overlooked?

Pedicle torsion possible

Vascular compromise

Can infarct

Examine atypical features

Slide 66 · Case 3 — numerous tags and metabolic risk

A 46-year-old with central adiposity has multiple neck and axillary tags and flexural velvety plaques.

What is an appropriate clinicopathologic interpretation?

Tags are nonspecific

Acanthosis nigricans is distinct

Risk-factor assessment

No diagnostic shortcut

Slide 67 · Case 4 — dome-shaped facial papules

A patient has multiple small pale facial papules, past spontaneous pneumothorax and affected relatives.

Why is “multiple skin tags” an inadequate conclusion?

Follicular papules possible

Pulmonary feature

Family history

BHD differential

Slide 68 · Case 5 — an evolving polypoid lesion

A new irregularly pigmented, ulcerated stalked skin lesion is described as a “skin tag” by the patient.

What is the immediate diagnostic priority?

Patient label not diagnosis

Evolution / ulceration

Suspicious pigment

Histologic confirmation

Slide 69 · The pathology pattern in one slide

Gross: Soft, often skin-coloured polyp with a narrow stalk.

Microscopy: Bland squamous epithelium enveloping a loose fibrovascular core.

Torsion can cause infarction; Clinically atypical growth requires a differential.

Slide 70 · Clinical synthesis

Usually benign and inconsequential; Treat for symptoms or cosmetic preference.

Common associations include age, obesity and diabetes—none are diagnostic alone.

Multiple isolated tags are not sufficient evidence for a hereditary cancer syndrome.

Slide 71 · Core and supplementary references

Primary textbook

Robbins, Cotran & Kumar. Pathologic Basis of Disease. 11th ed. 2026; Ch. 25, pp. 1037–1038.

Morphology and management

DermNet. Skin tag (Acrochordon). Https://dermnetnz.org/topics/skin-tag

Clinical review

Pandey A, Saleh HM. Skin Tag (Acrochordon). StatPearls. Updated 13 Dec 2025.

Slide 72 · Additional clinical references

Syndromic interpretation

Birt–Hogg–Dubé Syndrome. GeneReviews®. NCBI Bookshelf NBK1522.

Clinical practice guidance

ERN GENTURIS. Birt–Hogg–Dubé syndrome guidelines. Eur J Hum Genet. 2024.

Source fidelity

Original uploaded Robbins Markdown; excluded interleaved adnexal-tumor material.