More recent advances in research and treatment of histiocytic disorders have provided a high survival rate for patients with this disease. At the same time, as more patients have been followed long-term, the risk for permanent consequences has become more obvious. It is now known that survivors can have significant consequences related to the disease and/or its treatment, sometimes following long-term remission. Most of these issues tend to be directly related to sites of original disease involvement and may affect quality of life. Permanent consequences are not random with respect to the prior disease, rather they are the footprint of the disease on the affected area, with the exception of ND (neurodegenerative)-LCH. For example, if a child did not have LCH on their skin, they will not experience skin scarring. If they did not have LCH of the spine, they won’t have a spine deformity. Also, some of the permanent consequences are a result of treatment itself, for example osteoporosis from chemotherapy. It is believed that more than half of patients will develop permanent consequences.
Also known as “late effects,” some consequences such as neurologic symptoms may not show up until 10 or more years after diagnosis, while other consequences such as diabetes insipidus can occur when histiocytosis is diagnosed, or even before. For this reason, “permanent consequences” has been suggested as a better term than “late effects.” Although some consequences such as tooth loss, bone defects, and scarring of the skin may be the result of surgical treatment, it is believed that the disease process itself is responsible for most of the effects.
Permanent consequences occur more often with multisystem patients but are also seen in patients with single-system disease at diagnosis. In one study, over 70% of multisystem LCH patients had one or more permanent consequences, compared to 24% of single-system patients. Children are more at risk to develop consequences because the disease can interfere with growth and development, and the consequences have a longer time to develop.
Most of the permanent consequences are usually directly related to the sites of initial LCH involvement (not every patient will develop permanent consequences nor will those who do develop a late effect develop all):
- Diabetes insipidus (DI) – most commonly in patients with LCH involving more than one system (multisystem)
- Stunted growth/failure to achieve sexual maturity – in up to 10% of multisystem LCH
- Defects of bone/skull defects/facial asymmetry – in patients with LCH of the skull and of bones above the eyes, ears, jaw bone and mouth
- Loss of spinal height – in patients with collapsed back bone (vertebra plana)
- Loss of teeth/part of jawbone – in patients with LCH of the mouth
- Bulging of the eyes – in patients with LCH involving the bone above the eyes (orbital)
- Hearing loss – in patients with LCH involving the ears
- Scarring of the skin – in patients with skin LCH
- Scarring of the liver – in patients with chronic liver LCH (sclerosing cholangitis)
- Scarring of the lung – in patients with lung LCH
- Secondary cancers – very rare; leukemias or lymphomas
- Neurologic/cerebellar problems, which can include:
- Poor coordination/difficulty walking
- Bad handwriting
- Tremor/abnormal eye movements
- Difficulty with balance/unsteadiness/clumsiness
- Problems with speech and/or swallowing
- Loss of short-term and/or long-term memory
- Learning difficulty/poor school performance
- Difficulties with concentration/attention/processing
- Lower IQ score
- Organizational difficulties
- Behavior changes including aggression, eating disorders, depression, and difficulties with interpersonal relationships
Diabetes insipidus (DI) occurs more frequently in patients with LCH involving more than one system (or multisystem, in up to 12%) than those with disease limited to one system (single system). Patients with skull, facial, and/or eye bone lesions are at much higher risk of developing DI, and this risk is increased further if the disease remains active for a longer period or if it comes back (recurs). Although diabetes insipidus cannot be reversed, its symptoms can be successfully controlled with a hormone called DDAVP (or desmopressin).
Stunted growth is the second most common endocrine abnormality after DI and occurs in approximately 10% of children with LCH. It was shown in one study to occur in 43% of patients who had diagnoses of both LCH and diabetes insipidus. Stunted growth can be successfully treated with daily injections of growth hormone, usually for as long as the child is growing. This treatment appears to be safe and effective and is not associated with an increased risk of disease reactivation.
Orthopedic problems from lesions of the spine, leg bones, and arm bones are one of the more common consequences and may be seen in 20% of patients. These problems include collapse of the vertebrae, instability of the spine that may lead to abnormal spinal curvature, decreased spinal height, fractured bones, and inequality of leg length. In addition, since the skull and facial bones are frequent sites of lesions, abnormalities and asymmetry of the face may occur. Some bone/facial abnormalities can be corrected by orthopedic or cosmetic surgery.
Dental problems with loss of teeth have been a significant problem for some patients, either directly related to disease affecting the jaw or related to aggressive surgery for jaw disease. The potential for restoration/cosmetic repair can be discussed with a knowledgeable physician.
Eyes/Hearing concerns include residual eye bulging that can affect one or both eyes. Hearing loss was found in one study to affect 16% of children treated for LCH. Of those with CT or MRI abnormalities of the mastoid, 59% had hearing loss. Inner ear involvement has been known to cause loss of balance. Hearing aids or surgically inserted electronic hearing devices (cochlear implants) may be necessary.
Liver disease rarely happens, however when present, chronic liver disease may lead to scarring and destruction of the liver and, in rare cases, liver failure which may require liver transplantation.
Lung disease is believed to occur in less than 10% of patients, causes scarring and damage of lung tissue, and can result in long-term poor lung function with a higher risk for infections, shortness of breath, and lung collapse. In cases of severe damage, a lung transplant may be necessary for survival. Permanent damage, however, is less common in children, whose lung tissue can more easily regenerate. Patients with a history of lung involvement may have a lifelong susceptibility to lung disease associated with cigarette smoking.
Patients with histiocytosis have a slightly higher chance of developing secondary cancers when compared to the unaffected population; secondary cancers could include leukemia, brain tumors, and cancer of the lung, liver, bone, lymph nodes, and eyes. It has not been determined whether this is caused by treatment or a genetic predisposition. Cancer can occur at the same time as histiocytosis or can occur years afterwards.
There are two different forms of neurologic disease in LCH:
- The first form is called “granulomatous or tumorous” CNS-LCH which has an incidence of 10%-15% and tends to occur early in the course of LCH. This is when LCH forms tumors in the brain similarly to skin, bone, or other organs.
- The symptoms that are experienced depend on the specific location of the tumors. LCH within the pituitary gland causes DI and hormone problems. LCH within the lower part of the brain (brainstem or cerebellum) causes problems with speech, balance, and coordination. Other locations cause other issues. Brain MRI will show thickening of the pituitary gland stalk and/or LCH tumors in the brain. This form can be treated with chemotherapy, or sometimes targeted inhibitors, and most patients will have a favorable response.
- The second form is called neurodegenerative LCH (ND-LCH) or CNS-ND. This refers to neurologic problems, or abnormalities by MRI scan, that are not felt to be the direct result of LCH tumors.
- ND-LCH can have two manifestations, and patients can have either or both: (1) “Radiographic” ND-LCH, which means changes on brain MRI but without any neurologic symptoms. This occurs in up to 24% of all children with LCH in one study. (2) “Clinical” ND-LCH, where patients start developing neurologic, cognitive and psychological symptoms.
- Diabetes Insipidus is most common when there is involvement of the pituitary gland or with tumors in the skull bone or surrounding areas. DI can develop at the same time as these symptoms, or a patient may have had DI as part of their prior LCH. Only 25% of patients with radiographic ND-LCH will go onto develop clinical symptoms.
- Clinical CNS-ND is quite rare, occurring in 5% of patients with LCH and is more frequent in patients with multisystem disease, DI, and LCH involving the bones of the face or skull. Also, it is more frequent in patients with BRAF mutated LCH. Brain MRIs will show changes in the white matter of the cerebellum (posterior part of the brain) and brainstem (lower part of the brain), and less commonly in other areas as well. The onset of these symptoms occur many years (up to 10-15) after the resolution of LCH, although they may occur earlier. Initial symptoms include unstable walking (ataxia), speech problems (dysarthria), tremors, behavioral changes (anger, irritability) learning or psychiatric problems. Cognitive deterioration can occur in later stages. Since ND-LCH is not felt to be the result of LCH tumors, why this arises in patients with LCH, and why so many years after LCH illness, remains unclear. Some research has demonstrated that there are cells with BRAF mutations in the brain, and in the blood, of patients with ND-LCH; therefore, experts believe that ND-LCH is somehow related to cells with gene mutations, but exactly how is not known. This form is more challenging to treat, and does not usually improve greatly with chemotherapy. However, recent studies showed improvements in clinical and radiographic ND-LCH in patients receiving BRAF inhibitors such as dabrafenib or vemurafenib. Although these patients improve their neurologic function with these inhibitors, complete reversal of symptoms has not been reported.
- In addition, various forms of rehabilitation and teaching assistance can be helpful for these patients. These include assistance with learning and life skills; education about permanent consequences; teaching of repetition, reinforcement, and organizational skills; and placement of school/job accommodations. While the neurologic issues cannot be reversed, caregivers can provide tools that will help the patient increase his/her level of success.
In addition to compromised physical/cognitive function, histiocytosis survivors may experience quality-of-life issues such as anxiety/fear about possible relapse, sadness, anger, and depression. These feelings may be especially strong before follow-up visits, on illness-related anniversaries, or with onset of symptoms not related to the disease. For many people, these feelings will go away over time, while others may need psychological or psychiatric support. Finding a supportive network of other histiocytosis survivors can also be helpful.
If you or someone you love notices any of the above possible late effects, bring them to the attention of your physician. You may also consider speaking with your physician about a long-term follow up plan and care team. If you are in need of finding a physician, you can visit the Histio Physician Directory or give us a call at (856) 589-6606.
There are various support programs the Histiocytosis Association offers or shares from valued partners.
- On-line: You can subscribe to receive our emails for newsletters and to stay informed of important announcements regarding the latest information and research developments on the histiocytic disorders. The Association also maintains a Facebook page and private Facebook group for families and patients with this disease.
- Peer Chats: Sign up for virtual support chats, which are designed to provide a forum for patients and caregivers to connect as a community. In these meetings we lift one another up, offer support and compassion, and share our histio stories.
- Local support: The hospital where you or your child is being treated may have a support group for survivors of histiocytic disorders, rare diseases in general, or even cancer. Establishing face-to-face relationships with others going through similar experiences can be helpful.
- Ambassador Program: Connect with a Histio Ambassador in your local area or who may have shared a similar histio journey. Email outreach@histio.org to connect.
Because of the possible impact of permanent consequences on school/job performance, ability to lead an independent life, and overall quality of life, it is important that the patient be evaluated and followed long term, especially those with multisystem disease. Early recognition of any deficit will be important, so that appropriate rehabilitation and assistance can be planned and put into place.
After years of research and discussion among researchers, there are still considerable gaps in the understanding of histiocytosis and its neurological complications. Some authorities believe it is a process separate from disease activity, and others believe that early, effective therapy may prevent or reduce the complications.
In order to make further progress in this field, the Histiocyte Society has developed a clinical trial/study called LCH-IV which opened for registration in 2012 and is on-going. This includes new guidelines for diagnosis and treatment of CNS LCH, including repeated MRIs, standardized neurologic evaluation, and neuropsychological tests for all patients with CNS disease. The study will test whether longer therapy for active disease will reduce the rate of reactivation and development of complications. You may consult your health care provider to find out about possible treatment options.
If you are a histiocytosis survivor with permanent consequences, it will be important to educate yourself about available resources and stay updated about the latest research findings. This information will help you make informed decisions and play an active role in acquiring the best support and services available. In doing so, you will create the best chance for a successful outcome.