What is Osteitis Fibrosa Cystica (von Recklinghausen Disease of the Bone)?
Osteitis fibrosa cystica (OFC) is a rare bone disease often found in the advanced stages of another condition called hyperparathyroidism. This disease is also known as ‘von Recklinghausen Disease of the Bone,’ after Friedrich Daniel von Recklinghausen, a doctor who described it in 1891. That said, the disease was first mentioned in 1864 by Gerhard Engel. It was only in 1904 that a link between OFC and the parathyroid glands (small glands in your neck controlling calcium levels) was found.
“Osteitis fibrosa cystica” means “cystic bone destruction”, and it usually happens when there’s long-term overactivity in the parathyroid glands. This means that there’s too much parathyroid hormone (PTH) reaching the bones. In the past, this disease was a frequent side effect of hyperparathyroidism. However, it’s now quite rare, especially in Western countries. This is largely because of machines introduced in the 1970s-1980s that allowed doctors to spot asymptomatic hyperparathyroidism early on, preventing advanced-stage bone-related cases.
OFC can develop whenever there’s a sustained increase in PTH. This includes in primary, secondary, and tertiary hyperparathyroidism. Excessive activity in bone-absorbing cells can cause symptoms. These include, but are not limited to, swelling and pain in the bones, changes to bone shape, decreased bone mineral density, and fractures. These conditions may have one or more lesions, or injuries, which are sometimes known as “brown tumors”. They are called this because of the brown iron-containing substance deposited due to repeated minor injuries and tiny fractures. However, the name is somewhat misleading, as these “tumors” don’t actually have the capacity to become malignant, or cancerous. OFC can continue to progress if the parathyroid glands remain overactive and continue to stimulate the bone-absorbing cells. However, treating hyperparathyroidism, often with a surgery called a parathyroidectomy, can cure the patient and ultimately get rid of the disease.
What Causes Osteitis Fibrosa Cystica (von Recklinghausen Disease of the Bone)?
Osteitis fibrosa cystica (OFC), a bone disease, can occur when there is an overproduction of parathyroid hormone (PTH), which helps control calcium, phosphorus, and vitamin D levels in the blood and bone. These hormones can be overproduced due to a number of different conditions, like primary hyperparathyroidism that is both normocalcemic (normal calcium levels) and hypercalcemic (high calcium levels), secondary hyperparathyroidism, and tertiary hyperparathyroidism. It’s important to take special note that OFC is often seen in patients with advanced kidney disease.
Primary hyperparathyroidism, which usually occurs due to a noncancerous tumor (known scientifically as a ‘sporadic adenoma’) that happens in up to 85% of cases. It can also occur due to parathyroid cancer. Both scenarios have been connected with the occurrence of OFC. When dealing with cancer, it’s important to identify whether the OFC is resulting from the cancer spreading to the bones.
There are also certain genetic conditions that cause primary hyperparathyroidism, and these have all been associated with OFC. These conditions include an issue known as hyperparathyroidism jaw-tumor syndrome, familial isolated hyperparathyroidism, and another condition called multiple endocrine neoplasia.
In some cases, OFC can occur in a condition called pseudohypoparathyroidism, where PTH levels are high but without an increase in calcium levels. This usually occurs due to problems with how the organs respond to the hormone.
Lastly, OFC can also occur in certain cases when there’s an increase in PTH-related peptide, a protein that has similar properties to PTH. This condition such as adult T-cell leukemia, can cause PTH-related peptide levels to rise while suppressing actual PTH.
Risk Factors and Frequency for Osteitis Fibrosa Cystica (von Recklinghausen Disease of the Bone)
Hyperparathyroidism, a condition characterized by overactive parathyroid glands that results in excessive calcium in the blood, has now become more common since we have better ways to detect it. However, although there’s been an increase in diagnoses, severe cases of this condition have gone down. This condition used to commonly cause osteitis fibrosa cystica (OFC), a bone disorder, with around 69% of the cases having it. But this prevalence has decreased dramatically in the U.S over the past 50 years to 5% in primary hyperparathyroidism and 1.5% in secondary hyperparathyroidism. On the other hand, developing countries still see a high prevalence of OFC and other severe late-stage complications of hyperparathyroidism due to a lack of early detection facilities.
Brown tumors, the distinct abnormal tissue growth found in OFC, tend to be more common in people over the age of 50 and in females. It’s thought that hormones might have a role in this. There are other theories as to why OFC develops more frequently in individuals with parathyroid carcinoma. One reason could be the higher levels of parathyroid hormone (PTH) found in these individuals. For instance, about 90% of people with this type of cancer develop OFC, compared to only 5% with benign (non-cancerous) conditions.
Signs and Symptoms of Osteitis Fibrosa Cystica (von Recklinghausen Disease of the Bone)
Diagnosis of hyperparathyroidism often starts by knowing how long the patient had the disease, what treatments they’ve already had, and revisiting old medical records to understand the disease’s severity. Patients with OFC usually experience a prolonged or severe form of hyperparathyroidism that leads to problems with different organs. These may include:
- Kidney issues: Stones, failure, and too much urination.
- Abdominal problems: Inflammation of the pancreas, ulcers, nausea, vomiting, and constipation.
- Mental health challenges: Tiredness, feelings of sluggishness, memory issues, and depression.
Patients may also have bone-related symptoms. This can be observed in a history of fractures that happen easily, previous images showing weak or frail bones, reported pain, and deformed bones like curved long bones. Muscles might also show reduced reaction to stimulation, a possible symptom of too much calcium in the body. Most commonly, hyperparathyroidism affects the lower jaw, collarbone, pelvis, and ribs, which can indicate the presence of OFC. The diagnosis process should also involve examining the head and neck to feel for any abnormal lumps that suggest a parathyroid tumor.
Testing for Osteitis Fibrosa Cystica (von Recklinghausen Disease of the Bone)
Because of the rarity of OFC, or osteitis fibrosa cystica, routine image testing is typically not needed unless a patient shows certain symptoms or their medical history suggests a possibility of this condition. Typical signs on x-rays or other images that can indicate OFC include a pattern in the skull that resembles the sprinkling of salt-and-pepper, bone breakdown at the base and middle joint of the second and third fingers, changes in the end of the collarbone, and extensive brown tumors and bone cysts. It might be possible to see a general loss of bone density, an issue known as osteopenia, more often in the outer layer of bone (cortical) than the spongy bone (cancellous). When needed, a bone biopsy, which takes a small sample of your bone to be tested in a lab, can help identify if your symptoms are caused by OFC or a type of bone cancer. However, there is a potential risk with bone biopsies, as cancerous cells could potentially be spread during this process.
The lab tests that can indicate hyperparathyroidism, a common underlying issue in OFC, include high calcium levels in the blood. However, in some cases, the calcium levels may be normal. Also, the parathyroid hormone (PTH) levels in the blood may be elevated, or seemingly normal when they should actually be low. Other signs of hyperparathyroidism include low phosphate levels and high alkaline phosphatase levels, a sign of bone or liver disease. If parathyroid hormone levels are below normal, your doctor may suspect a type of cancer as the underlying cause of high blood calcium and will launch a search to identify that cancer, potentially with the help of a specialist in cancer treatment (oncologist). If you’re young or have a family history of hyperparathyroidism, your doctor may start looking for a genetic explanation and possibly refer you to a geneticist.
In the case of OFC, removing the parathyroid glands through surgery, known as a parathyroidectomy, is often the best treatment. To decide if surgery is right for you, your doctor will need to plan for it carefully. They may order an ultrasound of your neck to find your parathyroid glands. If further confirmation or more information about their location is needed, they may also order a sestamibi scan – a test that uses a small amount of radioactive material and a special camera to develop images of your parathyroid glands.
Treatment Options for Osteitis Fibrosa Cystica (von Recklinghausen Disease of the Bone)
The treatment for OFC, a kind of bone disease, focuses on dealing with the root cause, which is usually an overactive parathyroid gland – a condition called hyperparathyroidism. This often involves surgery to remove the overactive parathyroid gland. By doing so, the related tumors, known as ‘brown tumors’, are expected to shrink and disappear on their own, making further surgery unnecessary. In some circumstances, however, local surgical procedures might be performed if the brown tumors cause persistent deformity, fractures or discomfort.
In rare case reports, steroids have been used to shrink persistent tumors after parathyroid surgery. There are also examples of using bone tissue transplantation to treat OFC. In these procedures, the lesions were scraped away, and the cavity was filled with refrigerated bone chips, which helped resolve the issue.
It’s also very important to manage any underlying kidney disease, especially if you’ve got secondary hyperparathyroidism. This is because kidney disease can worsen hyperparathyroidism and the resulting OFC. People diagnosed with OFC might also have a deficiency in vitamin D, which can lead to more severe bone complications. It has been observed that oral vitamin D can aid the shrinking of brown tumors and alleviate the symptoms of OFC.
What else can Osteitis Fibrosa Cystica (von Recklinghausen Disease of the Bone) be?
Osteitis Fibrosa Cystica (OFC) is a less common condition, which means it’s not always a first consideration when doctors make a diagnosis. However, it’s still an important one to keep in mind because identifying it early can prevent invasive tests and procedures. Certain signs like high calcium levels (hypercalcemia) and degrading bone lesions might point towards either OFC resulting from hyperparathyroidism, or hypercalcemia due to cancer. The best way to distinguish between these two is by looking at Parathyroid Hormone (PTH) levels. In cancer-related hypercalcemia, PTH levels are usually low, while in OFC, these levels are either high or oddly normal.
Sometimes, OFC might appear similar to parathyroid cancer spreading to other parts of the body, even though this is very rare.
Additional conditions to consider in the diagnosis include:
- Giant tumours in the bone marrow
- Solid aneurysmal bone cysts
- Giant cell reparative granuloma
Telling the difference between these conditions can be difficult. Tests that measure the intake of certain substances in bones can sometimes mistakenly indicate cancer, softening of the bones (osteomalacia), or infection. Similarly, a type of imaging test known as a positron emission tomography (PET) scan can’t always tell the difference between harmful and non-harmful bone changes. Checking tissue under a microscope can also sometimes show similarities between these conditions, making it tricky to identify the correct one.
What to expect with Osteitis Fibrosa Cystica (von Recklinghausen Disease of the Bone)
Osteitis fibrosa cystica (OFC), a severe bone disorder, often gets worse with untreated or severe hyperparathyroidism, a condition caused by an overactive parathyroid gland. Although OFC can cause a great deal of discomfort, the outlook is generally good if the hyperparathyroidism is effectively managed.
OFC typically resolves after the removal of the overactive parathyroid gland(s) in a surgical procedure known as parathyroidectomy. This makes it unnecessary to surgically treat the brown tumors, which are abnormal bone structures associated with OFC.
Studies have shown that the bones start to regain their normal density and structure following the surgery. This leads to the healing of the brown tumors, which is confirmed through medical imaging and tissue examination. Additionally, patients also show noticeable improvement in their symptoms and general health status during their checkups.
Possible Complications When Diagnosed with Osteitis Fibrosa Cystica (von Recklinghausen Disease of the Bone)
If Osteitis Fibrosa Cystica (OFC) is not treated in time, it can result in constant pain, muscle weakness, abnormal bone structures, bone surface injuries, bending of bones, development of cysts and fractures. Moreover, patients with OFC are often found to have other complications linked to hyperparathyroidism. These include kidney stones, kidney failure, fatigue, stomach pain, mental health issues, and excessive urination.
Common Side Effects:
- Continuous pain
- Muscle weakness
- Abnormalities in bone structure
- Injuries on bone surface
- Bending of bones
- Development of cysts
- Fractures
- Kidney stones
- Kidney failure
- Fatigue
- Stomach pain
- Mental health issues
- Excessive urination
Preventing Osteitis Fibrosa Cystica (von Recklinghausen Disease of the Bone)
In the US, osteitis fibrosa cystica (OFC), a type of bone disorder, is a rare outcome (happening in less than 5% of cases) of hyperparathyroidism, which is a condition where the parathyroid glands produce too much hormone. This is more common in those with a longer and more severe history of the disease. Hypercalcemia, which is too much calcium in your blood, is often spotted during regular health check-ups, often before it causes damage to your organs. These check-ups are crucial as most patients don’t have any symptoms.
However, in parts of the world where regular health check-ups aren’t easily accessible, OFC and other issues related to hyperparathyroidism are more commonly seen. Therefore, it’s crucial to be aware of this unusual outcome in order to identify symptoms like bone pain, swelling, deformity, and weakness in cases of severe and untreated disease.
