Skin Lesions, Tumors & Melanoma: Types, Diagnosis & Treatment

Posted on Mar 28, 2025 in Biomedical Sciences

Primary and Secondary Skin Lesions: Types, Clinical and Morphological Characteristics

Primary Lesions

Macule → Small, circular, flat discoloration of the skin (e.g., freckles and flat moles)

Patch → A macule > 1 cm in diameter (e.g., vitiligo, senile freckles)

Papule → Solid, raised lesion

Plaque → A patch of closely grouped papules > 5 mm across

Wheal → Skin elevation caused by swelling that can be itchy and usually disappears soon after erupting (generally associated with allergic reactions, as to a drug or an insect bite).

Nodule → Solid lesion that has distinct edges and that usually is deeper rooted than a papule; diameter

Nodus → Solid lesion that has distinct edges and that usually is deeper rooted than a papule; diameter > 5 mm

Tumor → A nodule > 2 cm in diameter

Nodules are often described as palpable, hard masses distinct from the surrounding tissue when examined by touch.

Nodules are associated with, among other conditions, keratinous cysts, lipomas, fibromas, and some types of lymphomas.

Vesicle → Raised lesion

Bullae or Blisters → Vesicles that are > 5 mm across

These lesions may be the result of sunburns, insect bites, chemical irritation, or certain viral infections, as herpes.

Pustule → Raised lesion filled with pus (usually result of infection, as acne or impetigo)

Secondary Lesions

Erosion → Lesion that involves loss of epidermis

Ulcer → Lesion that involves loss of epidermis and dermis. Ulcers can result from acute conditions (e.g., bacterial infection or trauma), or from more chronic conditions (e.g., scleroderma or disorders involving peripheral veins and arteries).

Fissure → Ulcer that appears as a deep crack that extends to the dermis (e.g., athlete’s foot).

Scale → Dry, horny build-up of dead skin cells that often flakes off the surface of the skin. (Diseases that promote scale include fungal infections, psoriasis, and seborrheic dermatitis).

Crust → Dried collection of plasma or exudate (blood, serum, or pus). Often part of the normal healing process of many infectious lesions.

Excoriation → Traumatized or abraded skin caused by scratching, causing linear defect of epidermis (if goes deeper than stratum basal a scar results after healing).

Scar → Discolored, fibrous tissue that permanently replaces normal skin after destruction of the dermis (can be hypertrophic or atrophic).

Keloid → Exaggerated connective tissue response of injured skin that extends beyond the edges of the original wound.

Lichenification → Thickening of epidermis seen with exaggeration of normal skin lines (usually due to chronic rubbing or scratching of an area)

Atrophy → An area of skin that has become very thin and wrinkled. Normally seen in older individuals and people who are using very strong topical corticosteroid medication.

Seborrheic Keratoses, Hemangiomas, and Lipomas: Definition, Clinical Signs, Diagnostics, and Principles of Treatment

SEBORRHEIC KERATOSES

Definition

Common verrucous (of warts) pigmented tumor, usually after 40 years of age.

Clinical Signs

Seborrheic keratoses grow in crops (very unusual to see a solitary lesion).

Flat type

Smooth, flat, waxy plaques 0.5 to several cm on trunk; vary from tan to dark brown, sometimes with visible punctate inclusions.

• Acanthotic type

Elevated, dome-shaped, usually smooth, often heavily pigmented nodule with inclusions.

• Verrucous type

Paler 0.5 – 1.5 cm tumor with warty surface but without the punctate papillary hemorrhage so typical of viral warts.

• Stalked type

Pedunculated tags with surface changes of seborrheic keratosis, often in flexures or periorbital.

• Irritated seborrheic keratosis

Inflamed or irritated keratosis, secondary to trauma, irritation, or infection; tend to be smoother and less pigmented.

• Stucco keratoses

Pale, small keratoses typical on shins and back of feet, but occasionally on forearms and hands.

• Dermatosis papulosa nigra

Heavily pigmented small papules on the cheeks of blacks.

Diagnostics

Clinical examination; in questionable cases dermatoscopy is helpful.

Principles of Treatment

Curettage Cryotherapy Dermabrasion & laser ablation are alternatives

HEMANGIOMAS

Definition

Benign vascular tumor, which typically appears at birth or just thereafter.

Clinical Signs

Raised red to purple soft nodules (can become very large). ~30% can be seen at birth, but most appear later and all continue to grow. Tumors can be compressed, but do not disappear with diascopy.

Congenital hemangiomas typically are large nodules with a rim of dilated vessels; they are divided into rapidly involuting and non-involuting forms.

During the first months of life, hemangiomas can continue to grow. After about 1 year of age, no further growth is anticipated and regression starts. It may take many years and often leaves behind scar or loose skin.

Complications include:

Obstruction of vital structures: eyes, nose, mouth. Bleeding.

Diagnostics

Characteristic clinical findings.

Principles of Treatment

Treatment should be started early (before growth phase).

IPL (intense pulsed light) source, pulsed dye or Nd:YAG laser., Contact cryotherapy. Residual lesions or scars best excised.

Aggressive periorificial lesions: Intralesional or systemic corticosteroids (prednisolone 20 – 30 mg daily for 2 – 3 weeks). Interferon-α2 (systemic).

Sclerosing therapy or embolization also possible.

LIPOMAS

Definition

Accumulation of mature fat cells (most common benign soft tissue tumor).

Clinical Signs

Soft, lobulated, freely movable round or oval subcutaneous mass; usually appears in adult life; rarely symptomatic.

Variants include:

Angiolipoma

Usually painful, rich in small vessels that may have thromboses.

Spindle cell lipoma

Almost always on nape of older men; painless; bands of spindled fibrous cells mixed with fat cells.

Mobile lipoma

Usually on forearm; moveable over several cm; microscopically encapsulated; probably posttraumatic.

Lumbosacral lipoma

Congenital, often associated with spina bifida.

Diagnostics

• Clinical examination findings.
• Histology → normal fat tissue surround by a thin fibrous capsule.

Principles of Treatment

• Excision.

Ephelides and Other Benign Melanocytic Tumors: Definition, Clinical Signs, Diagnostics, and Principles of Treatment

EPHELIDES

Definition Localized hyperpigmentation caused by sun exposure that waxes and diminishes with seasons.

Clinical Signs

Irregular brown macules of varying shades of tan and brown. Much more common in skin types I & II; especially among redheads. Usually appear in childhood, flaring each summer;

Principles of Treatment Freckles are marker for ↑ risk of skin cancers. Preventive measures include: Sunscreens Sunlight avoidance

LENTIGO SIMPLES

Definition Localized hyperpigmentation secondary to ↑ in melanocytes at the dermoepidermal junction.

Clinical Signs

Sharply circumscribed, uniformly pigmented tan to dark brown macules (usually darker than ephelides).

No relation to sun exposure (unlike freckles).

Principles of Treatment None needed Sunscreen use / Sunlight avoidance For cosmetic reasons → cryotherapy or laser ablation can be performed.

CAFÉ-AU-LAIT MACULE

Definition Circumscribed tan macule, usually present at birth.

Clinical Signs

Irregular tan macules and patches varying in size from 1 to many cm. More than five café-au-lait macules > 1.5 cm suggest neurofibromatosis 1, but the macules can be sporadic or associated with a variety of syndromes.

Including: Neurofibromatosis I / II Albright syndrome Watson syndrome Bloom syndrome Ataxia-telangiectasia

Principles of Treatment Usually not required. Laser therapy may be used for cosmetic correction. If lesions are associated with neurofibromatosis → careful observation.

Benign Melanocytic Tumors (Melanocytic Nevi): Definition, Types, Clinical Features, Diagnostics, and Principles of Treatment

CONGENITAL MELANOCYTIC NEVI

Definition Melanocytic nevus present at birth.

Clinical Features

Most are heavily pigmented, have a papillomatous surface and contain hairs.

Lesions subdivided by size:

Small → Medium → 1.5 – 20 cm diameter Large → >20 cm diameter Giant lesions → involve an entire body segment

Diagnostics Clinical examination Dermatoscopy Photo documentation

Principles of Treatment

Small & medium lesions → excision.

Large lesions (excision may be problematic due to the size) → early dermabrasion or curettage removes much of the melanocyte load and improves cosmetic appearance.

Patients should be followed yearly. Any new nodules are highly suspicious and should be excised.

ACQUIRED MELANOCYTIC NEVI

Definition Benign proliferation of melanocytes (most common human tumor).

Clinical Features

Average patient has 20 – 40 melanocytic nevi.

Start as homogenous tan macules, which gradually darken but almost never > 6 mm. Later become papules or nodules.

Color range from skin-colored – to – tan – to – red-brown – to – almost black.

Surface varies from papillomatous to smooth.

Diagnostics

Careful clinical examination.

If many lesions or atypical lesions present: Photo-documentation Regular follow-up Patient should be instructed on “ABCDE rules” [asymmetry; borders; color; diameter; erythema/elevation]

Principles of treatment

Lesions that are likely to be traumatized, those which worry, or cosmetically bother the patient, can be excised.

NEVUS SPILUS

Definition Congenital lesion consisting of café-au-lait macule dotted with small melanocytic nevi.

Clinical features Irregular tan patch, (several cm in diameter), with numerous small dark macules (lentigenes) or papules (melanocytic nevi).

Principles of treatment Small lesions can be excised; otherwise patient should be followed and any changing, darker component should be removed.

HALO NEVUS

Definition Melanocytic nevus surrounded by hypopigmentation.

Clinical features Papular melanocytic nevus surrounded by white halo. Later nevus may fade or even disappear. Later, pigmentation comes back.

Principles of treatment Excision if desired. In multiple lesions cases → atypical nevus are excised.

SPITZ NEVUS

Definition Benign melanocytic nevus with atypical histologic pattern (easily confused with malignant melanoma).

Clinical features Red-brown papule or nodule, often on face or upper trunk. History of sudden growth.

Principles of treatment Excision. Atypical Spitz nevus cannot be separated with certainty from melanoma. They should be treated as melanoma.

Premalignant Skin Diseases: Definition, Clinical Features, Diagnostics, and Principles of Treatment

ACTINIC KERATOSIS Definition UVB-induced carcinoma in situ.

Clinical features Multiple sharply bordered irregular erythematous macules or papules with adherent scale, 0.5 – 2 cm size, always in sun-exposed areas. Individual lesions may become irritated or inflamed. ~1% of AK, yearly, expected to changes into invasive SCC (squamous cell carcinoma).

Diagnostics Clinical diagnosis. Histological diagnosis. Follow-up.

BOWEN DISEASE Definition Squamous cell carcinoma in situ on the skin.

Clinical features Slightly raised patch, tan to red-brown with variable scale, 1 – 3 cm in size. Most often on the trunk but can be anywhere.

Diagnostics Clinical examination Biopsy & histology

LEUKOPLAKIA Definition White patch on mucous surface, which will not rub off (candidiasis, usually, can be rubbed off). The white color is caused by moist hyperkeratosis.

Clinical features White patch on the buccal or labia mucosa. Can be verrucous (covered in warts) or ulcerated.

Diagnostics Clinical examination. Biopsy & histology (for DD (lichen planus or SCC)).

PRINCIPLES OF TREATMENT Electrodessication or cautery (requires local anesthetic) Laser therapy (requires local anesthetic) Cryotherapy Photodynamic therapy

Topical application of photosensitizes (aminolevulinic acid) followed by irradiation For multiple lesions: Topical 5-fluoruracil cream for 10 – 14 days Topical Imiquimod 3 x weekly for 6 weeks

Excision in local anesthesia (especially for thick and resistant to other treatment methods cases)

Malignant Epidermal Tumors

BASAL CELL CARCINOMA

Definition Low-grade malignant epidermis tumor, locally aggressive but almost never metastatic.

Epidemiology According to literature the incidence is 200/100000 in men, 100/100000 in women but gap narrowing. Incidence has doubled over past two decades. Most patients are > 50 yrs of age.

Clinical features Pearly nodules & telangiectases, most common on face or trunk (on trunk – multiple lesions). No mucosal lesions. Clinical-histological types

Nodular BCC → pearly telangiectatic nodule or papules, often with central ulceration. Superficial BCC → flat, red-brown patch, often with scaly and with a pearly border Pigmented BCC → pigmented nodule, papule or patch Sclerosing BCC → atrophic plaque Rodent ulcer → ulcer on forehead, scalp or midface Ulcus terebrans → aggressive BCC invading subcutis structures, bones, frequently fatal (but rare).

Diagnostics Clinical examination Biopsy & histological evaluation Dermatoscopy (14 MHz) can be used for evaluation of size

Principles of treatment and prevention

Surgical excision with histologic control of margins is the treatment of choice (recurrence rates )

Alternatives for superficial BCC or small lesions (lack of histologic control and higher recurrence rates): Cryosurgery Photodynamic therapy Curettage and electrocautery Laser ablation Topical Imiquimod or 5-FU (5-fluoruracil) cream 3 x weekly for 6 weeks Radiation therapy (multiple lesions or in difficult locations)

Preventive follow-up Every patient with BCC is likely to develop several more. Thus, patients should be checked yearly (in USA q 6 months is standard). New lesions can be identified and promptly treated at the same time as previous sites are monitored for recurrences. Prevention Avoidance of excessive sun exposure and use of sunscreen.

Prognosis According to literature (Rook’stext book of dermatology) → for primary BCCs, 5-year cure rates of 99% have been reported.

SQUAMOUS CELL CARCINOMA

Definition Malignant epidermal tumor arising from keratinocytes, with potential for local spread and metastasis.

Epidemiology According to literature the incidence is 100:100000 in men; 50:100000 in women; increasing in frequency yearly.

Clinical features

Usually present as hyperkeratotic papule or plaque, often with crust or ulceration. Difficult to separate from precancerous lesion. Growth rate and risk of metastasis (regional lymph nodes or visceral) are highly variable.

Diagnostics

Clinical examination and biopsy.

Any actinic keratosis or other carcinoma in situ that is resistant to therapy or ulcerated should be suspected of being a SCC.

Principles of treatment and prevention

Surgical excision with histologic control of margins is the treatment of choice (recurrence rates )

All other approaches are less than ideal (cryosurgery, photodynamic therapy, laser ablation, radiation therapy)

Inoperable or metastatic SCC are treated with chemotherapeutics (methotrexate or cisplatin)

Preventive follow-up Patients should be checked every 3 – 6 months for 5 yrs (interval depend on risk of MTS). Follow-up also includes checking for developing of additional tumors (most patients have multiple SCC precursor lesions).Prevention Avoidance of excessive sun exposure and use of sunscreen.

Prognosis

According to literature (Rook’stext book of dermatology) → in experienced hands, all the techniques give 5-year cure rates of ~90% in a wide variety of SCC at different sites.

Malignant Melanoma: Definition, Epidemiology, Clinical-Histological Types, Diagnostics, Prevention, Principles of Treatment, and Prognosis

Definition

Malignant tumor of melanocytes.

Epidemiology

The lifetime risk of malignant melanoma for white Europeans ↑ dramatically from 1:1500 in 1935 to 1:75 in 2000, representing a doubling of incidence every 10 – 15 yrs. In Australia and Southwestern USA, lifetime risk is 1:25. Uncommon in blacks and Asians (annual incidence 2 – 4/million).

Clinical-histological types

• Superficial spreading melanoma (SSM)

• Most common type (60%).
• Age peak 40 – 60 yrs.
• Horizontal growth phase and later vertical.
• Irregularly pigmented macule with polycyclic borders, usually > 6 mm.

• 

  Nodular melanoma (NM)

• ~20%.
• Age peak 40 – 60 yrs.
• Vertical growth phase with very short period of horizontal phase
• dark-brown papule or nodule, frequently ulcerated
• Worst prognosis

• Lentigo maligna melanoma (LMM)

• ~10%.
• More common for older patients (peaks > 60 yrs).
• Large irregularly pigmented macula or plaque in sun exposed sites (e.g. face, scalp).
• Better prognosis (very long horizontal growth phase).

• 

  Acral-lentiginous melanoma (ALM)

• 5%.
• Most common in dark-skinned people.
• Occurs on areas without hair follicles
• May be: subungual or digital

• Special variants of malignant melanoma

• Amelanotic (pink or skin-colored)
• Mucosal (involve mouth, pharynx, trachea, genitalia, anorectal region)
• Uveal
• Meningeal
• Gastrointestinal
• Occult melanoma (metastatic disease without primary tumor (after it complete regression on the skin)) 

• Tumor ≤ 1 mm thickness → 1 cm excision margin
• Tumor >1 mm thickness → 2 cm excision margin

• After tumor and metastasis excision adjuvant therapy with INF-α is recommended for high risk patients (stage IIB or higher)

Cases of metastatic MM (stage III)

• If LN metastasis (or SLN micrometastasis) are identified, radical LN dissection is required. After this operation adjuvant immunotherapy should be applied.

• Radiation therapy is the treatment choice for bone and brain MTS

• Polychemotherapy used for distant metastases (in stage IV) 

Prognosis

Evaluated via the 5 year survival rate and depend on the TNM classification stage.

Example in LT: