Spontaneous extradural hemorrhage due to Langerhans cell histiocytosis of the skull in a child: A rare presentation.

Eosinophilic granuloma (EG) represents a local form of Langerhans cell histiocytosis that occurs mostly in children. It usually presents with a gradually enlarging painless skull mass, and rarely presents a rapid clinical deterioration. This 7-year-old boy who was diagnosed with EG, based on a magnetic resonance imaging scan, after presenting with a painless right parietal swelling of 7-week duration. Three weeks prior his scheduled surgery, he presented to the emergency department with a 2-day history of sudden increased of the subcutaneous swelling associated with a headache, vomiting, and decreased the level of consciousness; there was no history of trauma. Brain computed tomography revealed a right parietal bone defect with large subgaleal and extradural hematoma. He underwent emergent surgical excision of the skull lesion and evacuation of the hematoma. Histopathological examination confirmed the diagnosis of EG. We aim to raise the awareness of physicians of this rare spontaneous hemorrhagic complication of EG and review the literature.

Introduction

Langerhans cell histiocytosis (LCH) is a rare group of disorders characterized by a proliferation of Langerhans-type histiocytes with a wide range of clinical presentations.[12] LCH clinical manifestations range from a solitary lesion in a single organ, most likely bone, to a more severe disseminated multisystem disease.[2]

Eosinophilic granuloma (EG) is a subtype of LCH that usually present in the form of a single destructive bony lesion.[23] EG occurs predominantly in children and adolescents.[34] The skull is the most commonly involved bone in children; femur, mandible, ribs, and vertebrae are other common sites of involvement.[45] Most children with skull EG are presented with a tender enlarging skull mass that sometimes proceeded with a history of head trauma.[367]

The presentation of EG of the skull with hemorrhagic sequelae is an extremely rare.[234] We present herein, a rare case of a 7-year-old boy with right parietal EG complicated by a spontaneous extradural hemorrhage that resulted in neurological deterioration. The literature was reviewed, and the possible pathophysiology was discussed.

Case Report

A 7-year-old boy presented to our clinic with a history of a painless right scalp swelling for 2 months. There was no history of headache or previous trauma. On examination, a right parietal swelling measuring around 20 mm in diameter that is fixed to the skull and free from the scalp was noted. The swelling was nontender, rounded in shape and firm in consistency with no fluctuation or pulsation. Neurological exam was intact. Skull X-ray revealed a right parietal skull defect measuring 20 mm × 20 mm with unclear margins. Brain magnetic resonance imaging (MRI) showed a 20 mm × 20 mm right parietal, extra-axial, well-demarcated, and heterogeneous lesion with skull bone erosion and subgaleal extension. The lesion enhanced intensely following intravenous contrast. No other lesions were noted, and no intracranial abnormality was detected [Figure 1]. The child was scheduled for elective excision of the mass and cranioplasty.

Figure 1

Axial (a) and sagittal (b) T1-weighted magnetic resonance imaging scans revealed a heterogeneous osteolytic mass in the right parietal region. The lesion intensely enhanced after contrast administration in the axial (c) and sagittal (d) T1-weighted magnetic resonance imaging scans

Three weeks prior to the scheduled admission, he presented to the emergency department with a progressive headache, vomiting, and decreased level of consciousness of 2-day duration. There was no history of trauma. General physical exam was within normal. The mass showed an increase in size (35 mm × 40 mm) since the previous examination and became tense, tender and cystic in consistency. Neurological examination revealed Glasgow Coma Scale of 13, and there was left sided mild hemiparesis.

Urgent computed tomography (CT) scan of the brain showed the same size of the right parietal bone defect, but there was a large subgaleal cystic mass that measures 32 mm × 35 mm × 35 mm, with an extradural hematoma measuring 52 mm × 21 mm × 53 mm causing a mass effect on the brain [Figure 2].

Figure 2

Selected axial sections (a-c) of cranial computed tomography scans demonstrating the skull defect with associated large subgaleal and extradural hematoma

The child was admitted and taken urgently to the operating room, and his preoperative laboratory tests including complete blood count and coagulation profile were within normal. Under general anesthesia, a right curved parietal incision around the swelling was made. Circumferential dissection of the cystic lesion was then performed initially. A bloody reddish fluid was aspirated from the cyst. The capsulated soft tissue lesion was excised completely and sent to pathology. The extradural hematoma was of the same color and was drained and sent for microbiology. The underneath dura looked healthy. The osteolytic bone edge was trimmed until the healthy bone was seen, and cranioplasty was not done.

Histopathology examination revealed polymorphic infiltrate composed predominantly of histiocytes and plenty of eosinophils. Hemosiderin-laden macrophages and multinucleated giant cells with areas of necrosis were also noted. The neoplastic histiocytes showed kidney-shaped and elongated nuclei with a longitudinal groove (coffee beans like), consistent with Langerhans histiocytes [Figure 3]. Immunohistochemistry revealed strong staining to S100, CD1a and CD68 in those Langerhans histiocytes confirming the diagnosis of Langerhans histiocytosis. There was no organisms’ growth on culture of the fluids obtained during surgery from the cyst or extradural space.

Figure 3

Photomicrograph showing polymorphic infiltrate of Langerhans histiocytes (polygonal cells with kidney-shaped and elongated nuclei had longitudinal groove) admixed with many eosinophils

The child had an uneventful postoperative period with complete recovery of his left hemiparesis and discharged home in a good condition.

He was regularly followed up without clinical or radiological recurrence of the lesion. The parents declined cranioplasty. CT scan at 6-year follow-up showed no recurrence of the lesion and spontaneous bone formation and closure of previous skull defect complete resolution of the [Figure 4].

Figure 4

Six-year follow computed tomography scan without (a) and with contrast (b) demonstrating no recurrence and spontaneous bone formation and closure of the skull defect

Discussion

EG is a mild focal form of LCH that represents around 70% of LCH cases.[4] At the time of diagnosis, more than 90% of children with EG would have a skull mass.[48] Most skull lesions would present with a tender enlarging mass usually located in the parietal bone.[8] Our patient was presented initially with an enlarging painless nontender mass. Rawlings and Wilkins presented one of the largest case series of patients with solitary EG of the skull and they reported that all their 26 patients were presented with a painful, or at the very least, tender to touch lesions.[8] In the other hand, painless and nontender skull EG lesions have been reported and appear not uncommon in the literature.[29]

The diagnosis of EG is usually carried out based on radiological and histopathological examinations.[8] On skull X-rays, EG appears as a sharply defined punched-out rounded osteolytic lesions.[1] Cranial CT scan, with a three-dimensional bone reconstruction, is usually very helpful in the diagnosis of EG.[1] Skull CT in thin slices can be useful to evaluate small osteolytic lesions that are hard to evaluate through skull X-ray.[1] As the outer layer of the skull is usually affected to a larger degree than the inner layer, EG lesions may show “beveled” edges resembling a shallow “V”-shaped groove in CT scans.[59] Also, CT scan can help identifying the extent of bone destruction and soft tissue involvement.[5] MRI would be more useful in delineating the extent of soft tissues lesions and their relationships to adjacent structures like dura mater or brain substance.[5]

Histopathology examination is usually used to confirm the diagnosis of EG.[1] Langerhans cells are derived from dendritic cell precursors and usually found in bone marrows.[5] They appear as large elongated cells with abundant cytoplasm.[5] They are also characterized by the presence of multiple nuclei with a typical groove.[1] EG is characterized by the presence of proliferative Langerhans cells and eosinophils.[5] Positive staining of S-100 protein, CD1a and anti-langerin (CD207) through immunohistochemistry is also helpful in confirmation of LCH diagnosis.[124]

Most pediatric patients with skull EG will present with an enlarging cranial mass.[4810] An association between the diagnosis of EG and preceding trauma has been observed and reported.[138] In the series of Rawlings and Wilkins, they reported that 38% of their cases were preceded by trauma.[8] Other series documented preceding head trauma in 33–50% of their reported cases.[4] However, the pathophysiology behind the occurrence of EG after trauma is still not clear.[13] Some authors postulated that trauma is just an event that attracts the attention to previously unnoticed EG lesions.[23]

The presentation of EG with extradural hemorrhagic sequelae is an extremely rare presentation.[4] In our literature review, we have identified only nine reported cases of EG, who presented with an extradural hematoma [Table 1]. We found that trauma anteceded the presentation of five cases while only five cases, including our case, were spontaneous in nature. A spontaneous nontraumatic extradural hematoma is a rare form of intracranial hematoma.[1213] Hassan et al. reviewed the cases of spontaneous extradural hemorrhage reported in the literature and could identify 52 cases.[13] He reported that the most common cause of spontaneous nontraumatic epidural hemorrhage was neighboring paracranial infections as paranasal sinusitis, chronic otitis media, or orbital infections.[13] Other causes include bleeding disorders, vascular malformations, and neoplastic conditions affecting the dura or the skull.[13]

Table 1

Summary of all reported cases of eosinophilic granuloma complicated by extradural hemorrhage

Traumatic injury to EG lesions could be the cause of the development of extradural hematoma in these lesions.[46] Head trauma could lead to a direct injury to EG lesion with secondary tumor rupture and hemorrhage into the epidural space.[6] In the other hand, spontaneous nontraumatic hemorrhage associated with EG seems not to have a clear etiology.[410] Many speculated possible mechanisms were proposed to explain the development of extradural hemorrhage including rupture of the tumor cyst, communicating with an epidural, vein and invasion of the venous sinus.[4710] Bhat et al. reported a case of EG with spontaneous epidural hematoma and attributed this finding to the stripping of dura from bone due to rapid tumor growth, erosion of the intradiploic and dural vessels and the bleeding of the dural neovascularization caused by EG.[12] In our case, the dura looked normal intraoperatively with no invasion by the tumor. We believe that the epidural hemorrhage is most likely due to an intratumor bleeding that extended into the extradural space. The presence of hemosiderin-laden macrophages with areas of necrosis in the histopathology examination of the tumor may also favor the hypothesis of intratumor hemorrhage. Although the presence of zones of necrosis and hemorrhage has been reported as a not uncommon finding in LCH cases and usually related to histiocytic function.[4]

Conclusion

The complication of EG during the disease course with extradural hematoma is considered an extremely rare event. Physicians should have a high index of suspicion for children diagnosed with cranial EG, who developed a headache, an increase in the mass size, and neurological symptoms.

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Conflicts of interest

There are no conflicts of interest.