Random Dermatology MCQ - Blue Rubber Bleb Nevus Syndrome

A 25-year-old man presents with chronic iron deficiency anemia refractory to oral supplementation. He has a history of multiple, soft, compressible, blue-black, rubbery nodules on his trunk, palms, and soles. Some of the lesions are painful, especially at night or with pressure. The most likely diagnosis and the primary cause of his anemia is:

A. Maffucci syndrome; anemia due to chronic disease from enchondromas.
B. Hereditary Hemorrhagic Telangiectasia (HHT); anemia due to recurrent epistaxis.
C. Blue Rubber Bleb Nevus Syndrome; anemia due to chronic, occult gastrointestinal bleeding from venous malformations.
D. Kaposi sarcoma; anemia due to bone marrow involvement by HHV-8.
E. Cutaneous mastocytosis; anemia due to splenic sequestration.

Correct Answer: C. Blue Rubber Bleb Nevus Syndrome; anemia due to chronic, occult gastrointestinal bleeding from venous malformations.

Answer and Explanation

The correct answer is C. This question describes the classic presentation of Blue Rubber Bleb Nevus Syndrome (BRBNS). The key clues are the characteristic cutaneous lesions (multiple, compressible, blue-black, rubbery nodules that can be painful) and the clinical scenario of refractory iron deficiency anemia in a young adult. The lesions are venous malformations. The most common and serious complication is gastrointestinal involvement, where similar venous malformations in the gut mucosa lead to chronic, occult bleeding, resulting in iron deficiency anemia. Pain is a common feature, often described as a feeling of "tightness" or "writhing."

Why the Other Options are Incorrect:

• A. Maffucci syndrome: This syndrome combines enchondromas (cartilaginous bone tumors) and venous malformations. While venous malformations are present, the bony tumors are a defining feature not mentioned here, and anemia is not typically a primary presentation.

• B. Hereditary Hemorrhagic Telangiectasia (HHT): This presents with mucocutaneous telangiectasias (small, flat, red lesions), not blue rubbery nodules. Anemia is due to recurrent bleeding from nasal or GI telangiectasias.

• D. Kaposi sarcoma: These are violaceous, non-compressible plaques or nodules, often on the lower extremities. They are caused by HHV-8 and are not typically described as "blue rubber blebs." Anemia from bone marrow involvement is a late and uncommon feature.

• E. Cutaneous mastocytosis: Lesions are typically brownish-red macules or papules (urticaria pigmentosa) that urticate when rubbed (Darier's sign). They are not blue, compressible, or rubbery. Anemia is not a typical feature.

Additional High-Yield Information for Exams:

• Pathology: The lesions are venous malformations, characterized histologically by dilated, thin-walled vascular channels in the dermis and subcutaneous tissue.

• Clinical Features:

  • Skin Lesions: Present at birth or early childhood, increase in size/number with age. The classic "blue rubber bleb" is compressible and refills slowly. Lesions can be tender.

  • GI Involvement: Can occur anywhere from mouth to anus, but most common in the small intestine. Bleeding may be occult or massive.

  • Other Sites: Venous malformations can also occur in the CNS, liver, spleen, and other organs, potentially causing serious complications.

• Genetics: Most cases are sporadic, though rare familial cases with autosomal dominant inheritance have been reported, linked to a mutation in the TEK (TIE2) gene.

• Differential Diagnosis: The combination of distinctive skin lesions and GI bleeding is highly specific. Other disorders with vascular lesions (Maffucci, HHT) lack the specific "blue rubber bleb" morphology.

• Associated Conditions & Prognosis:

  • Complications: The main complications are chronic anemia, acute GI hemorrhage, and intussusception from a lead-point lesion. Lesions in critical locations (CNS, airways) can be life-threatening.

  • Prognosis: Variable. Many have a normal lifespan with manageable symptoms, but morbidity from chronic anemia and pain is significant. Quality of life can be greatly impacted.

• Management & Rationale:

  • Rationale: The goals are to control GI bleeding and anemia, manage pain, and treat problematic cutaneous lesions.

  • First-line Investigations: For anemia, upper and lower endoscopy (and often capsule endoscopy or enteroscopy) to locate and characterize GI lesions. Iron studies confirm iron deficiency.

  • Treatment:

    • GI Bleeding: Iron supplementation (often intravenous). Endoscopic therapy (sclerotherapy, band ligation, argon plasma coagulation) is first-line for accessible lesions. For extensive or refractory disease, surgical resection of bowel segments may be necessary.

    • Cutaneous Lesions: Laser therapy (pulsed dye, Nd:YAG), sclerotherapy, or surgical excision for symptomatic or cosmetically concerning lesions.

    • Systemic Therapy: Sirolimus (rapamycin) has shown significant promise in reducing bleeding, lesion size, and pain, and is increasingly used for severe or extensive disease.