Pathology & Risk: Understanding the Presacral Mass

The presacral mass is often the most complex part of the Currarino triad. While these growths are frequently non-cancerous at the time of diagnosis, they require careful surgical removal and a detailed examination by a pathologist (a doctor who studies tissues) to understand the long-term risks ^[1][2].

Common Types of Presacral Masses

In Currarino syndrome, several different types of masses can occur in the space in front of the tailbone. A single patient may even have a “mixed” mass containing more than one type ^[1][3].

• Anterior Sacral Meningocele: This is not a tumor, but a fluid-filled sac of spinal fluid that pushes through a defect in the sacrum. It is directly connected to the spinal canal ^[1][2].
• Teratoma: This is a tumor made of different types of tissue, such as hair, muscle, or bone. Teratomas are classified as mature (mostly harmless, well-developed tissue) or immature (less developed tissue that has a higher chance of returning or becoming cancerous) ^[1][4].
• Dermoid or Epidermoid Cysts: These are slow-growing, fluid-filled sacs lined with skin-like tissue ^[3][5].
• Enteric Cysts: These are cysts lined with tissue similar to the lining of the gut or stomach ^[1].

Understanding Malignant Transformation

Although most presacral masses in Currarino syndrome are benign (non-cancerous), there is a small but documented risk of malignant transformation—where a previously harmless mass develops cancerous cells ^[4][6]. This risk is one reason why lifelong follow-up is recommended, even for adults diagnosed as children ^[7][8].

Specific rare cancers that have been found in Currarino-related masses include:

• Neuroendocrine (Carcinoid) Tumors: Slow-growing cancers that can develop within a teratoma or dermoid cyst ^[6][5].
• Mucinous Adenocarcinoma: A type of cancer that forms in mucus-producing glandular tissue ^[9][10].
• Primitive Neuroectodermal Tumors (PNET): A very rare, aggressive type of tumor that develops from early nerve cells ^[9][6].

The Pathology Report: A Completeness Checklist

After surgery, the pathologist will issue a report. This document is a “roadmap” for your future care. A complete report should include ^[9][4]:

1. Tissue Type: Does it identify the mass as a teratoma, cyst, or meningocele? ^[1]
2. Maturity Grade: For teratomas, does it list a grade (0–3)? Grade 0 is mature; Grades 1–3 indicate increasing amounts of immature (riskier) tissue ^[4][11].
3. Surgical Margins: Are the edges “clear” or “negative”? This means the surgeon likely removed the entire mass ^[12].
4. Specific Cell Foci: Does it mention any small areas of neuroendocrine cells or other malignant-looking cells? ^[9][10]
5. Neural Tissue: Does the mass contain nerve elements, which might suggest a connection to the spinal cord? ^[9]

If a mass is found to have immature or malignant components, your care team may expand to include an oncologist (cancer specialist) for additional monitoring or treatment ^[13]. This detailed pathology review ensures that no “hidden” risks are overlooked after the physical mass is gone. For information on routine screening moving forward, visit Survivorship & Family Screening.