Dermoid Cysts and Laboratory Abnormalities
A dermoid cyst on the ovary is unlikely to cause the combination of low iron saturation, elevated CEA, and consistently elevated platelet count you describe. While dermoid cysts can occasionally cause isolated tumor marker elevations, the specific pattern of abnormalities you mention suggests alternative diagnoses should be investigated.
Tumor Marker Elevations in Dermoid Cysts
Dermoid cysts can cause tumor marker elevations, but CEA is rarely affected:
- CA19-9 is the most commonly elevated marker in dermoid cysts, with a positive rate of 45.5% in confirmed cases 1
- CEA elevation is extremely rare, occurring in only 1.6% of dermoid cysts (2 out of 128 cases examined) 1
- CA125 shows the second highest elevation rate at 12.7%, while AFP, ferritin, and other markers are rarely elevated 1
- When CA19-9 is elevated in dermoid cysts, it may be associated with ovarian torsion and potential tissue necrosis 2
Low Iron Saturation and Anemia
Dermoid cysts do not typically cause low iron saturation or iron deficiency anemia. The available evidence mentions autoimmune hemolytic anemia as a rare complication of dermoid cysts 3, but this would present with a different hematologic pattern than iron deficiency (hemolysis causes elevated indirect bilirubin, elevated LDH, and low haptoglobin, not low iron saturation).
Elevated Platelet Count (Thrombocytosis)
Consistently elevated platelets are not a recognized feature of uncomplicated dermoid cysts. Reactive thrombocytosis typically occurs with:
- Chronic inflammation or infection
- Iron deficiency anemia (which you have)
- Malignancy
- Chronic blood loss
Clinical Interpretation
The combination of findings you describe—low iron saturation, elevated CEA, and persistent thrombocytosis—raises concern for:
- Gastrointestinal malignancy (CEA is primarily a marker for colorectal and other GI cancers, and these can cause chronic blood loss leading to iron deficiency and reactive thrombocytosis)
- Other malignancies that could explain all three findings
- Chronic inflammatory conditions with concurrent iron deficiency
Important Caveats
- If a dermoid cyst is present on imaging, it may be an incidental finding unrelated to your laboratory abnormalities 4
- Ruptured dermoid cysts can cause chronic peritonitis 3, which theoretically could contribute to thrombocytosis, but would not explain the CEA elevation or iron deficiency
- The extremely low rate of CEA elevation in dermoid cysts (1.6%) 1 makes it statistically unlikely that your dermoid cyst is responsible for this finding
You should undergo evaluation for alternative causes of these laboratory abnormalities, particularly gastrointestinal sources, including colonoscopy if age-appropriate and evaluation for occult GI bleeding, even if a dermoid cyst is present on imaging.