How do physians diagnose a mucous cyst accurately?
An experienced physician recognizes a mucous cyste by the typical appearance. A digital mucous cyst is most often solitary, flesh-coloured and dome-shaped. Most cyst are located dorsal at the joint nearest the fingernail. (DIP-joint).
In advance cases the overlying skin is very thin an the nail shows an irregular grow.
The patient prehistory gives further references. Most finger-cysts coexist with osteoarthritis. An experienced physician will noticed Heberden nodes at other fingers. (Heberden’s nodes are hard swellings that can develop in the joints closest to the end of the fingers, DIP-joint)
Many patients tell about a break open of the mucous cyst
The image on the left shows a finger cyst one week after a break open.
Translumination of the fingercyst with light confirm the diagnosis.
Why order the doctor an X-ray?
An X-ray of the finger can not show the finger cyst, but X-ray often show the narrwing of the joint space and the osteoarthritis of the joint nearest the fingernail.
Important is the X-ray, if an operation is an option! The X-ray often shows bone spurs (red arrow) dorsal of the DIP-joint. These bony spurs had to remove during an operation!
Is an ultrasonography evaluation of the finger necessary?
An ultrasonography evaluation can further confirm the diagnosis of a mucous fingercyst.
A mucous fingercyst is a small ganglion. During an ultrasonography evaluation, the doctor see in a finger cyst or in a ganglion a hypoechoic mass.
The images on the left shows the the typical appearance of a ganglion during ultrasonography evaluation.
(For a better understandig, I select a large ganglion of the wrist) The ultrasonography evaluation of a fingercyst show in principle the same picture.
Ultrasound ist possible in an office procedure and nearly all patients tolerated ultrasound better then a MRI.
Is a MRI or a CT necessary to confirm the diagnosis of a fingercyst?
No! A MRI or CT is a useful tool, if other tumors had to be considered. For example
- gigant.cell tumor of the tendon sheet,
- rheumatic noduls
- malignant tumors of a fingerbone….
The diagnosis of a finger cyst is in nearly all cases (for an experienced physician) not with difficulty.
In concluding this informational paper I would like to encourage you to address all questions you may have in connection with a finger cyst (finger ganglion) with your attending physician as this document does not constitute a replacement to a personal examination or consultancy through your doctor.