An adaptation by the Care4-Rare Project
You have made it to the map.
Part 8 of 8 — the full map. [ ← Before You Say Yes ]
You have made it to the map. If you arrived here directly, the seven companion pieces in this guided introduction are available from the Blog page — each one stands on its own, and together they tell the full story of why this map exists and how to use it.
The two patient-developed graphics are in the sidebar — a permanent visual reference for the conditions most central to this website.
If you arrived here from the two companion guides — the one about port wine stains and the one about the three confounded syndromes — you already understand the essential things. That the surface is not the whole story. That similar appearances can conceal different diseases. That slow-flow and high-flow are not the same condition and cannot be treated the same way.
What you are about to see is the full landscape of what the science has named.
More than 100 distinct classified entities. Three primary branches. Eleven subcategories. Each entry linked to a dedicated page where plain-language explanation, clinical summary, and source material are being built out — one entry at a time.
That number — 100 — is not here to overwhelm you. It is here because hiding it would be a disservice. The full map exists. You deserve to see it.
And here is the thing about a map with 100 entries: you are only looking for one. Everything else is context that helps you understand where your one entry sits, what surrounds it, and what distinguishes it from the conditions that look similar but are not the same.
How to Read What Follows
The compendium is organized in three branches.
Branch 1 — Neoplastic Vascular Tumors [NVT] Conditions driven by abnormal cell growth — cells dividing when they shouldn’t, creating new tissue. This branch includes infantile hemangiomas, which many families encounter first and which, crucially, involute over time. Most of us with lasting vascular conditions are not in this branch. But understanding it matters, because “hemangioma” was the wrong label given to many of us for years, and knowing why it was wrong clarifies what we actually have.
Branch 2 — Structural Vascular Malformations [SVM] Conditions in which vessels formed incorrectly during development. The cells are not dividing abnormally — the architecture was built wrong. This is where most of us live. Klippel-Trenaunay Syndrome. Sturge-Weber Syndrome. Parkes Weber Syndrome. Port wine stains in their various biological forms. Venous malformations, lymphatic malformations, combined malformations. The branch divides first by flow — fast or slow — then by vessel type, then by whether the condition is isolated or part of a broader syndrome. Each fork in that path narrows the map toward your entry.
Branch 3 — Potentially Unique Vascular Anomalies [PUV] Conditions still being classified — the ones science is still naming. This branch will grow as the field advances. It is here because intellectual honesty requires acknowledging that the map is not yet complete.
The Two Things Each Entry Carries
Every item in this compendium has two identifiers.
The ISSVA number places it within the international classification system maintained by the International Society for the Study of Vascular Anomalies — the framework that vascular specialists worldwide use to communicate about these conditions. That number is your connection to the professional literature and to specialists who speak this language.
The Care4-Rare catalog code connects the entry to this website. Each code links to a dedicated page where we are building plain-language explanations for families, clinical summaries for physicians, and sourced references for both. Pages are added as content is developed. Where a page is not yet complete, it will say so clearly — nothing here pretends to be finished.
The ◈ symbol between the two identifiers is the link. One click. One page. That is the navigation system for everything that follows.
A Word on the Science Behind This
The ISSVA classification is the international standard — not the only model, but the one most widely used by vascular anomaly specialists in the United States, and the one I first encountered at a patient-physician conference in 1997 that changed how I understood my own diagnosis.
European medicine uses the Hamburg Classification, which approaches the same landscape from a different organizational logic. Both are referenced and linked in the sidebar. Neither replaces specialist judgment. Both help you walk into a specialist’s office with better questions than you had before.
This compendium is built from the ISSVA model because I needed a foundation, and because the families and patients I have walked alongside over thirty years needed a single organized place to start from. It is adapted — organized, labeled, linked, and written for a reader who is not a physician but who deserves the same clarity a physician has.
The ISSVA Classification & Glossary 2025 is owned and copyrighted by ISSVA. Non-commercial use and reproduction are permitted without prior approval. Care4-Rare is a non-commercial patient advocacy project. Diagnosis is the realm of qualified medical professionals.
One Last Thing
When I first read the ISSVA classification in 2014, I cried.
Not from grief — though there was some of that. From recognition. For the first time I could see myself in a framework that reflected the actual complexity of what I had been living with for forty-two years. I was not a birthmark. I was not a hemangioma. I was a patient with a named syndrome, a documented biology, a community of others who shared it, and — finally — a map.
That map is what follows. It is not complete. It is living, the way the science is living. Entries will be added. Pages will be filled in. The field will continue to advance, and this compendium will advance with it.
But it is here. And your entry is in it.
Let’s find it.
Care4-Rare is a non-commercial patient advocacy project. Nothing here substitutes for evaluation by a qualified specialist in vascular anomalies. These materials are designed to support that conversation — to help you ask better questions and understand the answers more fully.
Direct links to the ISSVA classification, the ISSVA glossary, and the Hamburg Classification are available in the sidebar.
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