Langerhans cell histiocytosis (eosinophilic granuloma) of the skull mimicking nummular headache. Report of two cases

Abstract

Background Nummular headache is a rare, recently described topographic headache defined by the circumscribed coin-shaped area of pain. It is classified as a primary headache. There is debate about whether it is due to a peripheral or central disturbance, and its relationship to migraine. Case reports We report two patients with presumed nummular headache secondary to Langerhans cell histiocytosis, both with resolution of their headaches after surgical resection. Conclusion Imaging in patients with clinical features of nummular headache is recommended, as this and other cases highlight that it may be symptomatic. There are no distinguishing clinical features to separate nummular headache from secondary mimics, and treatment of the underlying cause may be curative.

Nummular Headache and Its Surgical Treatment

“…Of the 4 selected studies (Table 1 ), 1 was a case series 20 and the other 3 were case reports. 2 , 10 , 15 , 21 A total of 53 patients were included in the review on peripheral surgical management of NH. The sample size ranged from 1 to 49 patients.…”

“…However, most of the patients not only suffered from NH but also reported a variable headache history (92.8% in Guyuron et al). 20 Specific preoperative investigations were described in 3 of 4 studies: careful clinical and neurological examination associated to a Doppler signal within the painful area 20 ; skeletal studies, immunoglobulin level and paraprotein search, computed tomography scan, and magnetic resonance imaging (MRI) 10 ; and blood tests, including erythrocyte sedimentation rate, C-reactive protein, MRI, and ultrasound examination 15 . Characteristics such as dimensions, type of pain, and specific alterations of the affected area were described in only 3 case reports, while Guyuron et al did not report any information.…”

“…Characteristics such as dimensions, type of pain, and specific alterations of the affected area were described in only 3 case reports, while Guyuron et al did not report any information. Surgical strategies were also different with respect to the type of diagnosis: complete surgical removal of 2 eosinophilic granulomas (focal histiocytosis) and 1 fusiform aneurysm of the superficial temporal artery was described for secondary cases of NH 10 , 15 ; Dai et al removed the surface of the scalp from the symptomatic area to the tendinous part of the epicranius muscle and grafted it with healthy skin. Guyuron et al made an arterectomy/artery cauterization and a neurolysis/neurectomy through a 0.6- to 1.2-cm scalp incision in correspondence to the Doppler signal in all their patients.…”

“…Surgical excision of the identified lesions led to the complete disappearance of the symptoms in 3 of the 3 secondary NH cases. 10 , 15 Dai et al reported pain recurrence several days after excision of the clinically identified affected area. Finally, Guyuron et al 20 reported a significant reduction in headache frequency and severity, with a surgical success rate of about 70%.…”

“…Another topic of discussion regarding NH concerns the absolute overlap of its symptoms with some cases secondary to underlying extracranial and intracranial structural lesions, including Langerhans cell histiocytosis, 10 arachnoid cyst, 11 subtentorial meningioma, 12 localized calcific hematoma of the scalp, 13 craniosynostosis, 14 and aneurysmatic dilatations of arteries supplying blood to scalp. 15 Many of these secondary forms certainly support the peripheral mechanism for NH, considering especially that, in animal models, pain fibers crossing through the skull or running longitudinally within the endosteum are described.…”