Dermatologic Clues to Internal Disease: Selected Case Stories and Clinical Pearls

Conclusions

• The presentation’s main conclusion is that many striking skin findings are important clues to hidden systemic disease, so dermatologic examination can uncover serious internal disorders early.
• Carney complex is characterized by mucocutaneous lentigines, myxomas, and endocrine tumors, and recognizing the skin findings can point to a familial tumor syndrome.
• Leiomyomatosis with renal cancer is an autosomal dominant fumarate hydratase disorder in which skin leiomyomas and uterine fibroids should trigger early renal cancer screening and family counseling.
• Rothmund-Thomson syndrome presents with poikiloderma, sparse hair, and skeletal abnormalities, and RECQL4-related disease carries a notable osteosarcoma risk.
• Red or violaceous patches overlying bone or chest masses can signal paraneoplastic or tumor-associated processes such as AESOP syndrome, Hodgkin recurrence, or melanoma-associated Brenner sign.
• Massive localized lymphedema in severe obesity is not just a benign overgrowth but a lesion that can harbor or progress to angiosarcoma or squamous cell carcinoma, so it warrants complete examination and often excision.
• Chronic genital or perianal lymphedema-like changes can be caused by obesity, surgery, radiation, hidradenitis, cancer, or other lymphatic obstruction and should not be dismissed as simple dermatitis.
• Prurigo pigmentosa is an itchy reticulated eruption strongly linked to dieting, ketosis, weight loss, or bariatric states, and it tends to improve with diet change or tetracyclines rather than topical steroids.
• Skin biopsy can aid diagnosis even in neurologic disease, including Lafora disease, CADASIL, and synucleinopathies, showing that dermatopathology is increasingly useful beyond primary skin disorders.
• Pigmented lesions in the breast, genital, or acral skin are not always melanoma and may represent pigmented Paget disease, pigmented Bowen disease, or pigmented breast cancer, so pathology correlation is essential.
• Amyloidosis can produce purpura, waxy papules, and even acquired cutis laxa, and in some cases skin findings may be the first clue to an underlying plasma cell or lymphoproliferative disorder.
• Insulin-derived amyloidosis at injection sites can cause insulin resistance and dangerous dosing errors, so persistent injection-site lumps should be recognized as amyloidomas rather than simple lipohypertrophy.