Skull Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare dendritic histiocytic disorder that affects the bones, especially the skull.

Plain radiography, computed tomography and magnetic resonance imaging are the most used techniques for detection and characterization of the lesion. The use of ultrasound is less known, although it may be a valuable technique in detection and follow-up of superficially located lesions such as calvarial lesions. This case report describes an 8-year-old girl, in whom the lesion was initially detected by ultrasound. Furthermore, ultrasound was used to evaluate spontaneous resolution of the lesion. The knowledge of ultrasound characteristics may be important to avoid unnecessary radiation and gadolinium administration, particularly in a pediatric population ¹⁾

A 53-year-old man underwent a burr hole irrigation for chronic subdural hematoma, and the burr hole was covered with a burr hole button made of hydroxyapatite. Seven months after the first surgery, the connective tissue rapidly proliferated around the burr hole button, and the pathologic diagnosis was LCH. LCH recurred at 13 and 19 months after the first operation, with curettage performed each time. At 3 months after the final operation, no recurrence was identified on magnetic resonance imaging.

If there is rapid proliferation of connective tissue at an operative site where artificial material has been used, LCH should be considered ²⁾.

A young patient with a lytic skull lesion ³⁾.

A 36-year-old male patient presented with generalized tonic-clonic type seizure. Brain MR imaging showed a 3-cm mass lesion involving the right frontal lobe. It showed isointensity on T1-weighted images and hyperintensity on T2-weighted images. After gadolinium enhancement, the mass showed heterogeneous enhancement with perilesional edema and additional adjacent leptomeningeal enhancement. Special MR techniques focused on the enhanced lesion showed increased cerebral blood volume on perfusion images, no diffusion restriction on diffusion-weighted images, and a necrotic spectrum on MR spectroscopy. At surgery, we found a yellow mass and yellow tissue debris in the sulci adjacent to the mass and removed them. The final histopathologic diagnosis was LCH in the frontal lobe. The patient underwent scheduled adjuvant chemotherapy with cytarabine for 6 months and has been regularly followed up without any neurologic problem for 3 years.

In conclusion, additional sulcal enhancement around the mass lesion might be a clue MR imaging feature of intracerebral LCH, and special MR imaging techniques such as perfusion imaging, diffusion-weighted imaging, and MR spectroscopy could be helpful in differential diagnosis ⁴⁾.

A young patient with cranial bone classic HL, presumably originating from the skull without any involvement of lymph nodes. As the main clinical manifestation was only tumor mass in the skull without osteoscopic pain, the tentative diagnosis of Langerhans cell histiocytosis was histologically confirmed by an excisional biopsy. Before the final pathological diagnosis as classic HL, we noticed several small lesions in extranodal regions through systemic surveys, suggesting that the cranial lesion appeared antecedent to those lesions. This is a rare and instructive case of cranial bone HL for which a histological diagnosis has been meticulously made ⁵⁾.

Acute optic neuropathy can be elicited by Langerhans cell histiocytosis (LCH) arising in the sphenoid bone-ethmoid bone. Early decompression is the key to vision salvage. An endoscopic endonasal approach may be a good therapeutic option in this situation ⁶⁾.

Due to the rarity of skull Langerhans cell histiocytosis (LCH), correlations between abnormalities on magnetic resonance imaging (MRI) and pathological findings have not been fully evaluated. Only a few reports have as yet compared MRI of LCH infiltration and histological diagnostic features. A 22-year-old man with an unremarkable past medical history presented with headache followed by a nodular mass in the right parietal area. Gadolinium (Gd)-enhanced T1-weighted images showed a “mushroom-shaped” extension, extending from the subcutaneous to the intracranial space. The galeal tissue, the dura mater, and the cranium adjacent to the lesion showed enhancement on Gd-enhanced T1-weighted MRI. Histologically, diagnosis was LCH, with immunohistochemical positivity for S-100, CD68, and CD1a, and showed a MIB-1 labeling index of 29.5 %. By immunostaining, we confirmed LCH cells to be present in the galea with Gd enhancement and the skull without Gd enhancement on MRI. LCH cells might exist in the marginal cranium, if MRI shows only slight intensity change without Gd enhancement. Further evaluation to determine pathologically proven extent of LCH and its relation with neuroradiological diagnosis as well as clinical outcome is needed to understand heterogeneous response to surgical and/or nonsurgical treatment in LCH ⁷⁾.