Radiologic findings that aid in the reduction of misdiagnoses of Langerhans cell histiocytosis of the bone: a retrospective study

Abstract

Background This study aimed to identify the characteristic radiological signs for the diagnosis of Langerhans cell histiocytosis (LCH) of the bone. Methods We retrospectively studied 82 cases of LCH with bone lesions confirmed by pathology. Clinical and radiological features of the patients were analyzed. Results A total of 64 and 18 patients had single and multiple bone lesions, respectively. With regard to LCH with single bone lesions, 37.5% (24/64) of lesions were located in the skull and presented as bone destruction with or without soft tissue mass. The correct diagnosis rate of these lesions was 60.0% (9/15) in children and adolescents, but was only 22.2% (2/9) in adults. A total of 26.5% (17/64) of the solitary lesions were found in the spine. Of these, 88.2% (15/17) were located in the vertebral body and appeared to have different degrees of collapse, and 66.7% (10/15) of these lesions were correctly diagnosed. Of the unifocal lesions, 21.8% (14/64) were located in other flat and irregular bones and manifested as osteolysis. Only 21.4% (3/14) of these cases were correctly diagnosed. In total, 14.1% (9/64) of the isolated bone LCH lesions were located in the long bones. Of these, 77.8% (7/9) were located in the diaphysis and presented as central bone destruction with or without fusiform periosteal reaction and extensive peripheral edema, of which 42.9% (3/7) were correctly diagnosed before surgery or biopsy. With regard to LCH with multiple bony destructive lesions, 71.4% (10/14) of cases in children and adolescents were correctly diagnosed; however, all four cases among adults were misdiagnosed. Conclusion In all age groups, isolated diaphyseal destruction of the long bone with fusiform periosteal reaction and extensive peripheral edema, vertebra plana of the spine, and bevelled edge of skull defects accompanied by soft tissue masses strongly suggest LCH diagnosis. Moreover, the multiple bone osteolytic destruction in children and adolescents strongly suggests LCH diagnosis. Familiarity with these typical radiological signs of LCH is necessary to decrease misdiagnoses.

Answer: Multiple lesions of the skull in a 30-month-old girl

“…Langerhans cell histiocytosis (LCH) is rare, affecting 5-10 children per million (mostly under 15 years old). LCH is even rarer in adults, with an incidence of 1-2 adults per million per year, with an increased incidence in males and Hispanics [1][2][3][4][5]. The exact aetiology of this disease is unknown, with the debate still ongoing over whether it is a neoplastic or reactive disease in nature [2,3].…”

“…Vertebra plana is the typical appearance of LCH of the spine [2]. When the appendicular skeleton is affected, endosteal scalloping or fusiform periosteal reactions can be observed [3,5]. If MRI is used, the bone lesions will typically present as bone marrow oedema, with or without accompanying periostitis, these lesions being best seen on STIR sequences [2].…”

“…In cases where LCH presents as a solitary lesion, the differential diagnosis includes epidermoid and dermoid cysts and metastasis [5,8].…”

Adult Langerhans Cell Histiocytosis and the Skeleton

“…Therefore, a chronic lesion will typically have a sharply defined sclerotic margin and this can be regarded as a sign of the healing process [33]. Although in LCH with bone lesions the imaging findings are non-specific, isolated diaphyseal destruction of a long bone with fusiform periosteal reaction and peripheral oedema, vertebra plana of the spine, and the bevelled edge of the skull defects accompanied by soft tissue masses strongly suggest LCH [34]. Bone scintigraphy with technitium 99 m was used quite frequently in the past to detect bone lesions but it is not now considered a sensitive diagnostic approach and it is not anymore recommended in the evaluation of osseous involvement [35].…”

Multisystem Langerhans cell histiocystosis in a geriatric patient: case report

“…9 If the bone tissue is the affected one (which represents 80% of cases), it usually appears as a lytic tumor with centripetal distribution in large bones, especially at the level of the skull and vertebral bodies, being located in a smaller proportion in the appendicular skeleton; findings that are more solid in the population under 18 years of age, being found only in 20% of adults with this pathology. 6,7,[9][10][11] When it affects the skin, it is considered the second most affected organ (followed by bone) it appears as a morbiliform rash, the elemental lesion of which is the brown or reddish papule with or without crust. It has a generalized distribution, predominating in the thoracic, scapular, scalp, and sternum.…”