CASE 38: 52 y/o female patient with neck pain

This case was provided by Tecniscan Diagnostic Center. Let me warn you that we have no final diagnosis but the differentials are very useful to decide an invasive or conservatory approach. Patient referred chronic progressive neck pain associated with headache. She was treated with pain killers with little or no effect whatsoever. She had no other symptoms, no previous history of trauma, infection, medication or disease. Brain CT scan (not shown) was normal so the next step was the evaluation of a cervical MR. Here are the images:

 

With these findings, we conducted a CT, here are the images:

 

 

 

 

 

 Findings?...differentials?...later on the conclusion.

DX: Fetus-in-fetu

This is a rare case and one of the most bizarre I've seen. Findings in CT scan revealed a pelvic heterogeneous mass with free, soft borders, with fat and bone content that creates mass effect. It has a rudimentary spine and femur. Here are images from MIP and VR.

Fetus in fetu (or foetus in foetu) is a developmental abnormality in which a mass of tissue resembling a fetus forms inside the body. There are two theories of origin concerning "fetus in fetu". One theory is that the mass begins as a normal fetus but becomes enveloped inside its twin. The other theory is that the mass is a highly developed teratoma. "Fetus in fetu" is estimated to occur in 1 in 500,000 live births.

If patient were a female, the possibility of a Teratoma is more likely to consider.

Few reports describe antenatal diagnosis of Fetus-in-fetu (FIF). Preoperative diagnosis can be made on plain radiographs and CT scan/MRI. The presence of vertebrae, long bones, bones of hands and feet etc are the common radiological findings. Visualization of a non-homogenous mass with bones especially vertebrae is considered pathognomonic of FIF. Failure to visualize vertebrae however does not rule out possibility of FIF.

Most of the reported cases describe FIF suspended with an umbilical cord like stalk in an amnion like membrane containing fluid- equivalent to amniotic cavity. In few cases, the exact blood supply could be identified; in most of cases the blood supply was thought to come from the abdominal wall where amnion like membrane was in close approximation to it. The FIF are usually anencephalic, with the vertebrae and limb-buds (long bones and bones of hands/feet can also present), and acardiac (rarely heart was found). In few cases vertebral column was not found however presence of mature enteric nervous plexi and melanocytes in the skin depicted the fetus would have passed the primitive streak stage of notochord development.


Sorry for the delay in the conslusion. Thank you Dr. Imran Jindani, Sarath Chand Velamala, Sreedhar Settipalli and Amutha Csp for your comments on FB page.




http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3418045/pdf/ajcr-3-9.pdf