Abstract
Background
Internal haemorrhagic pachymeningiosis (IHP) is a rare disease characterized by a fibrous thickening and inflammatory infiltration in dural space mimicking chronic subdural hematoma. The pathogenesis of IHP is not entirely clear yet and treatment is still controversial.
Objective
We want to emphasize the importance of differentiating pachymeningiosis from chronic subdural hematoma as distinct pathological entities.
Patients and methods
The records of five selected cases of IHP histologically confirmed were reviewed, focusing onset, neuroimaging, surgery and outcomes.
Conclusions
IHP is most likely underestimated. Only through multidisciplinary approach it is possible to plane the proper therapeutic strategy. The diagnosis of IHP is confirmed by definitive histology but in some cases is possible with intraoperative frozen section.
Keywords: Internal haemorrhagic pachymeningiosis, Chronic subdural haematoma, Diagnosis, Histology, Surgery
Introduction
Chronic subdural hematoma (CSH) is one of the most common disorders observed in neurosurgical practice. The CSH most often occurs in patients ≥ 60 years with brain atrophy, a shrinking or wasting away of brain tissue due to age or disease. In all symptomatic patients with focal neurological deficits surgery is mandatory (1).
The best surgical procedure of CSH is still controversial (2, 3). Most common surgical techniques are a simple one burr hole or, as alternative option, a double burr hole (frontal and parietal). Twist drill craniostomy (TDC) is a less invasive procedure but the craniotomy is often required.
Internal haemorrhagic pachymeningiosis (IHP) is a rare disease characterized by a fibrous thickening and inflammatory infiltration in dural space. The prevalent hypothesis is that IHP is preceded by an intradural dissociation at the inner layer of dura mater called pachymeningiosis dissecans (4–8). Clinical and neuroradiological diagnosis and proper treatment of IHP are not yet defined.
The aim of this study is presenting five selected cases of HIP, discussing onset, diagnostic strategy and surgical treatment.
Patients and methods
Between 1999 and 2011, we observed 5 patients (4 male, 1 female; age range 37–88 years, mean 69.2) (Table 1). All patients were admitted to the Emergency Department. Three patients complained of headache associated with hemiparesis, one patient was in coma status, and the last developed only headache without other symptoms. All patients had history of a head injury and three of hypertension. None of the patients had history of bleeding disorder or alcohol abuse.
Table 1.
CASISTICA PERSONALE 2000–2006. SUTURE MECCANICHE.
| Case | Sex/Age (yrs) | Previous head injury | Neurological deficits | Site | Surgery | Outcome (3 year follow up) |
|---|---|---|---|---|---|---|
| 1 | F/88 | No | Coma (GCS* 6/15) | Left hemisphere | Two burr holes and craniotomy | Died for heart disease 4 months after surgery |
| 2 | M/32 | Yes (1 month before) | Left hemiparesis | Right hemisphere | One burr hole and craniotomy | Complete remission |
| 3 | M/81 | Yes (3 months before) | Right hemiparesis | Left fronto-parietal region | Two burr holes and craniotomy | Complete remission |
| 4 | M/74 | Yes (2 months before) | Right hemiparesis | Left fronto-temporal region | One burr hole and craniotomy | Complete, remission |
| 5 | M/71 | Yes (2 months before) | Only headache | Left hemisphere | Two burr holes and craniotomy | Died for renal failure 1 month after surgery |
GCS, Glascow Coma Scale
In all cases preoperative computed tomography (CT) was performed (Figures 1 and 4).
Figure 1.
Case 1. Pre-operative computed tomography.
Figure 4.
Case 5. Pre-operative computed tomography shows hemispheric hypodense area in left fronto-parietal region.
Surgical procedure
All patients had a preliminary drill hole (two times in three patients for the morphologic characteristics of subdural hematoma, i.e. the presence of fibrous septa) for the evacuation of CSH and redo surgery (craniotomy) to remove the IHP histologically confirmed by the biopsy performed in all cases during the first intervention (Table 1). The excision of the lesion has never difficult.
Results
In all patients post-craniotomy CT (Figures 2, 3, and 5) showed almost complete disappearance of subdural hematoma.
Figure 2.
Case 1. Post-craniotomy computed tomography shows the disappearance of the lesion.
Figure 3.
Case 1. Post-craniotomy computed tomography shows the disappearance of the lesion.
Figure 5.
Case 5. Post-craniotomy computed tomography shows the disappearance of the lesion.
Definitive histological examination of surgical specimens confirmed IHP. The IHP lesion is clearly subdural even though dural leaflets appeared infiltrated by fibrous tissue. Macroscopically the lesion has hard-elastic consistency and is dark red in color with yellowish patches (Figure 6). Histology shows a fibrous thickening of the dura. Fine vascular network is fragile and bleeding is common. Macrophages with hemosiderin mixed with neutrophils or fibroblasts are frequent (Figures 7 and 8). Around the site of bleeding significant mixed inflammatory infiltrate with fibrin and in some cases calcified areas are present. In the early stages we can find a dissociation of the internal fibrous layer of the dura and vessels hyperplasia, with giants, enlarged, thin small vessels. As the process becomes chronic, new bleedings are possible with haematoma reorganization by granulation tissue formation (5).
Figure 6.
Case 5. Surgical specimen (40×23mm).
Figure 7.
Histology. Internal haemorrhagic pachymeningiosis. Fibrous thickening of the inner layer of the dura mater with thickened small vessels) surrounded by inflammatory infiltrate (H&E, 100x).
Figure 8.
Histology. Internal haemorrhagic pachymeningiosis. Recent bleeding below the fibrous thickening of the dura with chronic inflammatory infiltrate in the meninges (H&E, 50x).
The follow up of patients at three years from craniotomy showed total remission of the neurological deficits in 3 patients. Two patients died for other disease: one for renal failure 1 month after craniotomy and another one after 3 months for heart disease.
Discussion
Internal haemorrhagic pachymeningiosis (IHP) is an uncommon lesion characterized by fibrous thickening of the dura mater in which spontaneous or traumatic bleeding can occur. In fact, IHP has clinical evidence when complicated by major bleeding. The brain is flattened and deformed by haematoma. Liquor pressure is often lowered (5, 7).
We don’t know the pathogenesis of IHP but the early stage seems to be the so called pachymeningiosis dissecans, i.e. a relaxation/dissociation of the fibers of the inner layer of the dura mater, with the formation of tissutal gaps. In these gaps easily bleeding small vessels develop (4, 8). As the process becomes chronic we find, often bilaterally, a stratified fibrous thickening of the dura mater with necrotic material and blood.
As reported by Wepler (6), the pathomorphological substrate of IHP is a proliferative alteration of the fine vascular network of the inner layer of the dura. It is possible that this alteration is preceded or enabled by pachymeningiosis dissecans (6, 8).
In presence of dura mater previously altered (with intradural lesions), the head trauma can lead to the formation of a hematoma but also of a bulky which in any case will be clearly intradural (4, 7). In traumatic chronic subdural haematoma the hematoma is in subdural space, and the organization of the haemorrhage occurs within both of the dura mater and of the leptomeninges (7, 9–12).
In differential diagnosis should also be considered the idiopathic hypertrophic pachymeningitis. This disease is a chronic, fibrosing, non-specific inflammatory process that involves the dura mater of the brain, particularly the falx cerebri and the tentorium. Idiopathic hypertrophic pachymeningitis neuro-imaging mimics small acute subdural hematoma (13, 14).
In many case the cause of IHP is unknow (5). Predisposing factors of IHP are: head injury; haemorrhagic diathesis; vitamin deficit; alcohol abuse; intrathecal therapy (methylprednisolone or chemotherapy); complicated meningitis; degenerative disease and collagen vascular disease or sarcoidosis; inflammatory conditions, such as cerebral atrophy involving meninges. As reported by Galatioto et al. (7), is critical to differentiate chronic traumatic subdural hematoma from IHP, which is a specific disease entity.
Histologic diagnosis is important for proper therapeutic strategy, if necessary with complete craniotomy.
Conclusions
The IHP is a rare, most likely underestimated and insidious specific disease. IHP must be histologically differentiated from chronic subdural hematoma. The proper treatment is controversial and depends on multidisciplinary collaboration.
References
- 1.Gautschi OP, Gallay MN, Kress TT, et al. Chronic subdural hematoma - assessment and management. Praxis (Bern 1994) 2010;99(21):1269–77. doi: 10.1024/1661-8157/a000275. [DOI] [PubMed] [Google Scholar]
- 2.Sakakibara F, Tsuzuki N, Uozumi Y, et al. Chronic subdural hematoma: recurrence and prevention. Brain Nerve. 2011;63( 1):69–74. [PubMed] [Google Scholar]
- 3.Carangelo B, Peri G, Signori G, et al. Chronic hemispheric subdural hematoma in a patient with antibodies antiphospholipid syndrome: case report. J Neurosurg Sci. 2009;53(3):141–3. [PubMed] [Google Scholar]
- 4.Virchow R. Das hamatom der dura mater. Verh Phys Med Ges Wurzburg. 1857;7:134–42. [Google Scholar]
- 5.Carangelo B, Siciliano M, Del Basso De Caro ML, et al. Internal hemorrahagic pachymeningiosis (PEI). Reflections on two cases. Gazz Med Ital - Arch Sci Med. 2000;159:1–4. [Google Scholar]
- 6.Wepler W. Zur Pathogenese und Begutachtung des chronischen Hämatoms der Dura mater. Zentralbl Allg Pathol. 1954 Feb 22;91(6–8):406–412. [PubMed] [Google Scholar]
- 7.Galatioto S, Gullotta F. Considerazioni patogenetiche sulla pachimeningiosi emorragica interna. Acta Neurol (Napoli) 1970;25(5):578–81. [PubMed] [Google Scholar]
- 8.Raso M. Trattato di anatomia patologica clinica. 3 Ed. Piccin - Nuova Libraria; Padova: 1986. [Google Scholar]
- 9.Friede RL. Incidence and distribution of neomembranes of dura mater. J Neurol Neurosurg Psychiat. 1971;34:439–446. doi: 10.1136/jnnp.34.4.439. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Niggemeyer H. Internal hemorrahagic pachymeningiosis (subdural effusion and membrane syndrome) Monatsschr Kinderheilkd. 1969;117(5):427–8. [PubMed] [Google Scholar]
- 11.Heifer U. Pachymeningiosis hemorrhagica interna and organized traumatic subdural hematoma. Dtsch Z Gesamte Gerichtl Med. 1963;54:58–63. [PubMed] [Google Scholar]
- 12.Heifer U. Non-traumatic intradural hemorrages in pachymeningiosis dissecans with secondary, fulminating hemorrage into the subdural space. Frankf Z Pathol. 1962;72:155–66. [PubMed] [Google Scholar]
- 13.Park IS, Kim H, Chung EI, et al. Idiopathic hypertrophic cranial pachymeningitis misdiagnosed as acute subtentorial hematoma. J Korean Neurosurg Soc. 2010;48(2):181–184. doi: 10.3340/jkns.2010.48.2.181. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Im SH, Cho KT, Seo HS, Choi JS. Idiopathic hypertrophic cranial pachymeningitis presenting with headache. Headache. 2008;48( 8):1232–5. doi: 10.1111/j.1526-4610.2008.01140.x. [DOI] [PubMed] [Google Scholar]