logo Signs of internal malignancy

Systemic dermatology

Signs of internal malignancy


  • Recognise potential cutaneous signs of malignancy.

A group of rare cutaneous disorders are associated with internal cancer. However, benign variants are more common for the majority of these conditions.

Acanthosis nigricans
  • Hyperpigmented velvety thickening of neck, axillae and other body folds.
  • Associated with insulin resistance, obesity and malignancy of GI or GU tract. Malignant variety affects hands and feet.
  • Heliotrope eyelids; erythema face, neck, upper trunk; flat papules on knuckles.
  • Associated in elderly with malignancy of breast, lung, GI tract, ovary and uterus.
Necrolytic migratory erythema
  • Crusting erosions around mouth, nose and genitals.
  • Associated with glucagonoma (α-cell tumour of pancreas).
Acquired ichthyosis
  • Sometimes associated with cachexia and particularly with non-Hodgkin’s lymphoma
Paraneoplastic acrokeratosis (Bazex syndrome)
  • Psoriasis-like or honeycomb keratoderma of hands, feet, nose, ear
  • Associated with squamous cell carcinoma of upper respiratory or gastrointestinal tracts
Erythema gyratum repens
  • Migrating and pruritic annular erythema with concentric whirling rings.
  • Associated with lung cancer.
Sign of Léser Trelat
  • Eruptive seborrhoeic keratoses arising in patient with cancer
Cowden’s disease
  • Autosomal dominant cutaneous hamartomas (esp. tricholemmomas)
  • Associated with breast and thyroid cancers.
Paraneoplastic pemphigus
  • Severe erosions of mucous membranes associated with erythema multiforme-like blistering on trunk and limbs.
  • Characteristic direct immunofluorescence staining.
  • Associated with malignancy especially lymphoma.

Some malignant skin tumours may indicate the presence of an internal cancer.

Bowen’s disease
(squamous cell carcinoma in situ)
  • Red scaly plaques.
  • When multiple and in non-sun exposed sites, may be due to arsenic ingestion, associated with internal malignancies.
Paget’s disease
  • Eczema-like red scaly plaque.
  • Mammary Paget’s is associated with intraductal breast cancer.
  • Extramammary Paget’s (flexural lesions) associated with eccrine, apocrine, GI or GU cancer.
Cutaneous metastases
  • Solitary or multiple firm or hard dermal nodules deposited via lymphatic or haematogenous spread.
  • Most often breast, GI, lung, melanoma, GU origin.
T cell lymphoma
  • Erythematous bizarre-shaped scaly patches, plaques and nodules or erythroderma
  • CTCL is a malignancy of helper T cells (CD4+) and involves entire lymphoreticular system but nearly always first manifests in the skin.
B cell lymphoma
  • Asymptomatic reddish, purple or brown plaques and nodules.
  • Sometimes confined to the skin (rare) but more often associated with systemic B cell lymphoma.
Kaposi’s sarcoma
  • Mucocutaneous violaceous plaques and nodules
  • Vascular neoplasm in immunocompromised especially acquired immunodeficiency syndrome
  • Often systemic.