Case records of the Massachusetts General Hospital. Weekly clinicopathological exercises. Case 9-2000. A 41-year-old man with multiple bony lesions and adjacent soft-tissue masses

The triptych of mixed histiocytosis: a systematic review of 105 cases and proposed clinical classification

Histiocytoses are one of the ultimate diagnostic challenges that every physician face at least once in his/her life. Giving their protean manifestation and differentiated therapeutic needs, histiocytosis requires extensive characterization and multidisciplinary management. Mixed histiocytosis is an emerging group of syndromes defined by the overlap of Langerhans cell histiocytosis and another histiocytic disorder of different type. Despite rare, it may account for up to a fifth of systemic histiocytosis patients in some series. In this work, we comprehensively review for the first time the clinical, radiological, histopathological and molecular features of mixed histiocytosis in children and adults. Moreover, we propose a clinical classification in three groups that differentiate patients with systemic involvement and worse overall survival to other groups with more localized manifestations and indolent behavior, wanting to ease their recognition and treatment. Interestingly we also found that mixed histiocytosis harbor BRAFV600E mutations with a higher frequency comparing to all other histiocytoses, and may therefore benefit of specific inhibitory drugs.

Erdheim-Chester Disease: A Case Report

Patient: Female, 56

Final Diagnosis: Erdheim-Chester disease

Symptoms: Slurred speech • unsteady gait • walking difficulties

Medication: —

Clinical Procedure: —

Specialty: Oncology

Association of both Langerhans cell histiocytosis and Erdheim-Chester disease linked to the BRAFV600E mutation

Histiocytoses are a group of heterogeneous diseases that mostly comprise Langerhans cell histiocytosis (LCH) and non-LCH. The association of LCH with non-LCH is exceptional. We report 23 patients with biopsy-proven LCH associated with Erdheim-Chester disease (ECD) (mixed histiocytosis) and discuss the significance of this association. We compare the clinical phenotypes of these patients with those of 56 patients with isolated LCH and 53 patients with isolated ECD. The average age at diagnosis was 43 years. ECD followed (n = 12) or was diagnosed simultaneously with (n = 11) but never preceded LCH. Although heterogeneous, the phenotype of patients with mixed histiocytosis was closer to that of isolated ECD than to that of isolated LCH (principal component analysis). LCH and ECD improved in response to interferon alpha-2a treatment in only 50% of patients (8 of 16). We found the BRAF(V600E) mutation in 11 (69%) of 16 LCH lesions and in 9 (82%) of 11 ECD lesions. Eight patients had mutations in both ECD and LCH biopsies. Our findings indicate that the association of LCH and ECD is not fortuitous and suggest a link between these diseases involving the BRAF(V600E) mutation.

Erdheim-Chester disease and pituitary involvement: a unique case and the literature

An early thirties man diagnosed with Erdheim-Chester disease (ECD) was simultaneously disclosed to have hypogonadotropic hypogonadism, central adrenal insufficiency, and GH deficiency in addition to central diabetes insipidus (CDI). Pituitary magnetic resonance imaging (MRI) showed swelling in the stalk, enlargement of the anterior lobe with delayed enhancement, and loss of high intensity of the posterior lobe on T1-weighted images, suggesting of pituitary involvement of ECD. Three months after starting treatment with interferon α and zoledronic acid, polyuria and polydipsia were ameliorated without DDAVP, accompanied with improvement of MRI. Simultaneously technetium-99m bone scintigraphy showed improvement, accompanied with a relief of bone pain and high fever. In contrast, he developed secondary hypothyroidism with slight enlargement of anterior pituitary gland without relapse of CDI, suggesting of different responses to treatment with interferon α between anterior pituitary lobe and posterior one. So far he continues to be replaced with deficient hormone replacement therapy. As for bone pain, it remains to be controlled with the decreased levels of bone resorption marker with decreased abnormal uptake in bone scintigraphy although zoledronic acid was discontinued for osteonecrosis of the jaw. For four years, he has not showed new involvement at other organs besides bones and the pituitary. While CDI is known to be very common in ECD, improvement of CDI has been reported in a few cases. Other endocrine manifestations, especially with detailed endocrine status, have been also reported in limited cases. Thus we report this case and review the literature.

A case of erdheim-chester disease with asymptomatic renal involvement

Erdheim-Chester disease is a rare non-Langerhans-cell histiocytosis involving bones and multiple organs. Its clinical course can vary, from an asymptomatic state to a fatal disease, with renal involvement being a common cause of death. A 41-year-old man presented with a 10-month history of bilateral lower limb pain. Left perirenal soft-tissue infiltration had been found incidentally two years earlier. No progression of the lesion or deterioration of renal function was observed for a period of two years. At admission, plain radiography and magnetic resonance imaging of the patient's lower limbs showed patchy osteosclerosis. Biopsy of the tibia revealed histiocytic infiltration, which was found to be positive for CD68 and negative for CD1a. This report describes an unusual case of Erdheim-Chester disease involving a stationary course of disease with no specific treatment for a long period of time.

A case of osteoarthropathy due to Erdheim-Chester disease with overlapping Langerhans' cell infiltration

Histiocytosis sometimes involves the joints, and is one of the important differential diagnoses of osteoarthropathy. A 31-year-old man presented with recurrent fever and bilateral knee arthritis two years prior to admission. He also showed the hypopituitary mass lesion and partial hypopituitarism. X-ray studies showed both osteosclerotic and osteolytic lesions near the large joints. Histological findings of bone biopsy revealed foamy macrophage infiltration, which were CD68+CD1a-S100-, and Erdheim-Chester disease was diagnosed. In addition, CD68+CD1a+ Langerhans' cells also aggregated in the same lesions, and we thought this case was a rare variant of Erdheim-Chester disease with overlapping histiocytic invasion.