The posterior part of the pituitary gland and pituitary stalk can be affected in patients with LCH, causing central diabetes insipidus. (Refer to the Endocrine subsection in the Multisystem Disease Presentation section of this summary for more information.) Anterior pituitary involvement often results in growth failure and delayed or precocious puberty. Rarely, hypothalamic involvement may cause morbid obesity.
Thyroid involvement has been reported in LCH. Symptoms include massive thyroid enlargement, hypothyroidism, and respiratory symptoms.
Multisystem Disease Presentation
In multisystem LCH, the disease presents in multiple organs or body systems including bone, abdominal/gastrointestinal system (liver and spleen), lung, bone marrow, endocrine system, eye, CNS, skin, and lymph nodes.
Bone and other organ systems
Patients with LCH may present with multiple bone lesions as a single site (single-system multifocal bone) or bone lesions with other organ systems involved (multisystem including bone). A review of patients with single-system multifocal bone presentation and patients with multisystem including bone presentation who were treated on the Japanese LCH study (JLSG-02) found that patients in the multisystem including bone group were more likely to have lesions in the temporal bone, mastoid/petrous bone, orbit, and zygomatic bone (CNS risk). Patients with multisystem including bone presentation had a higher incidence of diabetes insipidus, correlating with the higher frequency of lesions in the noted facial bones. There was no difference in the outcome of treatment, which was more intense in the JLSG-02 study than in the LCH-II study.
In LCH, the liver and spleen are considered high-risk organs, and involvement of these organs affects prognosis. Involvement in this context means the liver and spleen are enlarged from direct infiltration of LCH cells or as a secondary phenomenon of excess cytokines, which cause macrophage activation or infiltration of lymphocytes around bile ducts. LCH cells have a portal (bile duct) tropism that may lead to biliary damage and ductal sclerosis. A percutaneous (peripheral) liver biopsy may not be diagnostic of the infiltrate that tends to be more central in the liver, but will show the upstream obstructive effects of distal biliary occlusion. Hepatic enlargement can be accompanied by dysfunction, leading to hypoalbuminemia with ascites, hyperbilirubinemia, and clotting factor deficiencies. Sonography, computed tomography (CT), or MRI of the liver will show hypoechoic or low-signal intensity along the portal veins or biliary tracts when the liver is involved with LCH.