Chronic Subdural Hematoma with Metastatic Involvement of the Dura and the Hematoma Outer Membrane from Esophageal Cancer: A Case Report

Aya NAMBA; Yosuke ISHII; Ayana SAWAYANAGI; Ryosuke SAKAI; Yongson KIM; Akihito SATO; Yoshiki OBATA; Shigeru NEMOTO

doi:10.2176/jns-nmc.2026-0035

Abstract

Chronic subdural hematoma associated with malignant tumors rarely occurs and is frequently characterized by early recurrence and poor prognosis. Dural metastasis is the most common underlying mechanism; however, metastatic involvement of the hematoma outer membrane is extremely rare. A case of rapidly recurrent chronic subdural hematoma caused by metastatic esophageal cancer involving the dura mater and the hematoma outer membrane is reported. A 74-year-old man with stage IVB esophageal squamous cell carcinoma presented with persistent headache without a history of head trauma. Magnetic resonance imaging revealed a right-sided chronic subdural hematoma with midline shift, and burr-hole drainage was performed. However, symptoms recurred after 3 days. Contrast-enhanced magnetic resonance imaging revealed a mildly enhancing mass attached to the falx cerebri. Craniotomy revealed a dural metastatic lesion, and pathological examination confirmed poorly differentiated squamous cell carcinoma. Identical metastatic tumor cells were also found in the hematoma outer membrane. The patient recovered without new neurological deficits and subsequently underwent whole-brain irradiation. Six weeks post treatment, a cystic intracerebral lesion developed adjacent to the resection cavity and was successfully treated by cyst drainage. The patient remained free of recurrent chronic subdural hematoma and neurological deterioration until the terminal stage but ultimately died from complications associated with primary esophageal cancer 110 days after the initial surgery. Metastatic disease should be considered in patients with rapid recurrence of chronic subdural hematoma after burr-hole drainage. In such cases, craniotomy with resection of both the dural metastasis and hematoma outer membrane may be considered as a treatment option to reduce recurrence and preserve neurological function in selected patients.

Introduction

Chronic subdural hematoma (CSDH) associated with malignant tumors without trauma is characterized by a high recurrence rate and poor prognosis.¹^,²⁾ Dural metastasis is the most common underlying mechanism of malignancy-related CSDH. The hematoma outer membrane is a rare site of metastasis from malignant tumors causing CSDH.³^-⁶⁾ Here, we present a case of rapidly recurrent CSDH after burr-hole drainage, in which subsequent craniotomy revealed metastatic involvement of esophageal cancer in the dura mater and the hematoma outer membrane.

Case Presentation

A 74-year-old man presented to our gastroenterology department with dysphagia and hemoptysis. He was diagnosed with stage IVB esophageal carcinoma with local invasion into the aorta and bronchus, along with multiple lymph node metastases. He underwent concurrent chemoradiotherapy using the 5-fluorouracil and cisplatin 700/70 regimen (40 Gy in 20 fractions).

Although the patient had no history of head trauma, magnetic resonance imaging (MRI) performed to evaluate a 10-day history of persistent headache revealed a right-sided CSDH with midline shift (Figure 1A). Burr-hole drainage was performed on the same day. On dural incision, the hematoma outer membrane appeared typical of CSDH. Opening the membrane led to the expulsion of dark-reddish hematoma fluid, and macroscopic findings were characteristic of a typical CSDH.

Figure 1

Radiological findings obtained during the clinical course of a chronic subdural hematoma and a tumor attached to the falx cerebri.

(A) Preoperative fluid-attenuated inversion recovery magnetic resonance imaging (MRI) indicating a right-sided chronic subdural hematoma (CSDH) with midline shift. The high-intensity lesion in the right corona radiata is consistent with a chronic infarction.

(B) Postoperative brain computed tomography (CT) after the initial burr-hole drainage revealing adequate evacuation of the CSDH, with residual subdural hematoma along the falx cerebri.

(C) Brain CT performed 3 days after the initial surgery revealing recurrence of the right-sided CSDH and enlargement of the subdural hematoma along the falx cerebri.

(D) Contrast-enhanced MRI performed after the second burr-hole drainage showing a mildly enhancing mass lesion (white arrow) attached to the falx cerebri within the subdural hematoma. No obvious thickening of the hematoma outer membrane was observed.

(E, F) Brain MRI obtained 6 weeks after tumor resection showing a newly developed cystic lesion with thin ring enhancement on contrast-enhanced imaging (E) and worsening pericystic cerebral edema on T2-weighted imaging (F).

(G, H) Brain CT obtained 2 weeks after cyst drainage revealing no recurrence of the CSDH or cystic lesion.

Postoperative computed tomography (CT) on the following day showed adequate hematoma evacuation and midline shift improvement. However, a hematoma within the interhemispheric fissure along the falx cerebri persisted and increased in size compared with the preoperative scan (Figure 1B). Despite initial alleviation of headache and resumption of oral feeding, recurrent headache and loss of appetite developed on postoperative day 3. CT revealed a recurrence of the right-sided CSDH with enlarged interhemispheric hematoma (Figure 1C). A second burr-hole drainage was performed through the same burr hole, yielding symptomatic improvement.

Contrast-enhanced MRI to evaluate the early recurrence showed a mass with mild enhancement adjacent to the right side of the falx cerebri (Figure 1D), raising suspicion of dural metastasis from esophageal cancer. Given the high risk of rebleeding, craniotomy was performed 4 days after the second burr-hole procedure.

Intraoperative findings

After opening the dura matter, the outer membrane of the CSDH was exposed (Figure 2A); the outer membrane was partially resected and submitted for histopathological examination (Figure 2B). Subsequently, a soft, grayish–white tumor attached to the falx cerebri was identified (Figure 2C). The lesion indicated a well-circumscribed interface with the surrounding brain parenchyma. Gross-total resection was achieved; the dural attachment was removed extensively, and the adjacent dura was subsequently cauterized.

Figure 2

Intraoperative and histopathological observations of the hematoma outer membrane and a tumor attached to the falx cerebri.

(A) Intraoperative view after dural opening revealing the reddish outer membrane of the chronic subdural hematoma. The area indicated by the white arrow was resected and histopathologically examined.

(B) Hematoxylin and eosin (H&E) staining of the hematoma outer membrane showing clusters of poorly differentiated tumor cells with marked nuclear atypia and pleomorphic nuclei, accompanied by hemosiderin deposition (original magnification ×200).

(C) Intraoperative view indicating a soft, grayish–white tumor (white arrow) attached to the falx cerebri (black arrowheads).

(D) H&E staining of the tumor revealing clusters of poorly differentiated tumor cells with marked nuclear atypia and pleomorphic nuclei (original magnification ×200).

(E) Immunohistochemical staining for cytokeratin (AE1/AE3) showing diffuse and strong positivity in tumor cells (original magnification ×200).

(F) Immunohistochemical staining for cytokeratin 5/6 showing focal and weak positivity in a small number of tumor cells (original magnification ×200).

(G) Immunohistochemical staining for p40 showing negative staining in tumor cells (original magnification ×200).

Pathological findings

Hematoxylin and eosin staining showed clusters of undifferentiated tumor cells with marked nuclear atypia and large pleomorphic nuclei (Figure 2D). Immunohistochemical analysis revealed positivity for α-smooth muscle actin, cytokeratin (AE1/AE3), cytokeratin 5/6, and vimentin, and negativity for p40, findings overall consistent with poorly differentiated squamous cell carcinoma (SCC) (Figure 2E-G). These findings were consistent with those of the primary esophageal biopsy, confirming metastatic disease. Moreover, pathological evaluation of the outer membrane of the convexity hematoma revealed similar pathological findings (Figure 2B).

Postoperative course

The initial postoperative course was uneventful, without new neurological deficits. After whole-brain radiation therapy (20 Gy in 5 fractions), the patient was discharged home with a modified Rankin Scale score of 1. However, 6 weeks post craniotomy, weakness graded MMT 4/5 developed in his left upper and lower extremities. MRI revealed a cystic lesion with mild ring enhancement in the right parietal lobe adjacent to the resection cavity, accompanied by progressive cerebral edema (Figure 1E, F).

The patient was readmitted, and cyst puncture caused draining of approximately 30 mL of dark-reddish serosanguineous fluid, resembling typical CSDH contents. His motor weakness improved subsequently, and no further recurrence of either the CSDH or cyst was observed (Figure 1G, H). However, the clinical course was later complicated by tracheal perforation and pneumonia associated with primary esophageal cancer, and the patient died 52 days after the cyst puncture (110 days after the initial burr-hole procedure).

Discussion

CSDH can occur even without trauma, with reported nontraumatic etiologies including meningitis,⁷⁾ coagulopathies, and intracranial hypotension, malignant tumors.⁴⁾ CSDH secondary to metastasis from malignant tumors accounted for approximately 2.3% of all patients with CSDH.¹⁾ Reported primary tumors include prostate, breast, lung, and gastric cancers, many of which are adenocarcinomas; however, the distribution varies among studies, and comprehensive epidemiological data remain limited.⁸^,⁹⁾ Most cases of CSDH caused by metastatic tumors are due to dural metastasis; however, only a few exceptional cases of metastasis to the outer membrane of the hematoma³^-⁶⁾ and 1 case of metastasis to the hematoma cavity were reported.¹⁰⁾ To our knowledge, this case was the first to reveal metastasis to the hematoma membrane and dura.

Esophageal cancer is predominantly SCC in Japan,¹¹⁾ and dural metastasis from esophageal cancer appears to be exceedingly rare regardless of histological subtype.¹²^,¹³⁾ Although adenocarcinoma has been reported to show a higher incidence of brain metastasis than SCC,¹¹^,¹⁴⁾ there are insufficient data to determine whether a similar difference exists for dural metastasis. Therefore, our findings do not support routine brain MRI surveillance in patients without symptoms but rather suggest that contrast-enhanced neuroimaging should be considered when neurological symptoms and atypical imaging findings are present or when there is unusually early recurrence of CSDH.

Importantly, this case showed a distinct metastatic mass in the dura mater, but no obvious abnormal findings such as thickening of the hematoma outer membrane, in contrast to previously reported outer membrane metastasis cases, were observed.³^-⁶⁾ Nevertheless, pathological examination revealed metastatic carcinoma in the dura mater and hematoma outer membrane. Although mild enhancement of the outer membrane was observed on contrast-enhanced MRI, the intensity was comparable to that typically seen in nonneoplastic CSDH membranes,¹⁵⁾ making radiological distinction exceedingly challenging. This increases the possibility that prior cases diagnosed as dural metastasis–associated CSDH may have included unrecognized metastatic involvement of the outer membrane owing to the absence of characteristic imaging findings. The precise route of tumor spread to the hematoma outer membrane remains unclear. Possible mechanisms include hematogenous metastasis through the middle meningeal artery, direct infiltration of a metastatic lesion involving the falx cerebri, or dissemination resembling meningeal spread. Given that metastatic tumor cells were identified in the convex outer membrane, distant from the falx cerebri, tumor cells were considered to be distributed widely within the hematoma outer membrane in a pattern analogous to that of meningeal dissemination.

In the present case, whole-brain radiotherapy (WBRT) was selected as the postoperative therapy because the presence of dural metastasis raised concern for potential occult leptomeningeal or multifocal intracranial dissemination. Dural metastasis has been reported to indicate both local and distant intracranial progression, suggesting the possibility of widespread intracranial disease even when imaging findings appear localized. Therefore, broader radiation coverage, such as WBRT, may be considered in selected cases. However, current evidence indicates that survival outcomes are generally comparable in different treatment modalities, including surgery and radiotherapy, and no clear superiority of WBRT to focal radiation techniques has been established.¹⁶^,¹⁷⁾

Several mechanisms have been proposed for dural metastasis–induced CSDH, including angiogenesis associated with metastatic infiltration, rupture of fragile neovessels secondary to venous occlusion, and hemorrhagic effusion caused by angiodesmoplastic reactions.⁴⁾ Moreover, the hematoma outer membrane plays a crucial role in CSDH pathophysiology by producing exudative fluid and contributing to recurrent bleeding.⁷⁾ Inflammatory cells and mediators within the outer membrane and hematoma cavity promote membrane proliferation and persistent fluid accumulation.⁷⁾ The phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway within the outer membrane has been activated, enhancing endothelial proliferation and increasing vascular permeability through nitric oxide production.¹⁸⁾ Vascular endothelial growth factor (VEGF), a key upstream PI3K/Akt activator,¹⁸⁾ is frequently elevated in patients with cancer,¹⁹⁾ suggesting that VEGF-driven PI3K/Akt signaling may accelerate CSDH formation in malignancy, particularly when the outer membrane is infiltrated by tumor cells. Cancer-associated coagulopathy, including bone marrow suppression and hypoproteinemia, may also contribute,²⁰⁾ although not detected in this case.

In cases of CSDH secondary to dural metastasis, burr-hole drainage alone carries a substantial risk of early recurrence.¹^,²⁾ Early contrast-enhanced MRI may help diagnose dural metastasis in patients with malignancy and guide the need for more definitive intervention. Craniotomy with wide resection of the dural metastatic lesion and hematoma outer membrane may reduce recurrence and help preserve neurological function. In our patient, no neurological deterioration occurred until the terminal stage, indicating that aggressive surgical management helped maintain the quality of life, although the overall prognosis remained poor owing to the advanced nature of primary malignancy.

The cystic lesion developed 6 weeks after craniotomy was suggestive of chronic encapsulated intracerebral hematoma (CEIH), a rare condition characterized by gradual enlargement within a fibrous capsule. Its proposed mechanisms—neovascularization, excessive fibrinolysis, and cerebrospinal fluid influx driven by osmotic gradients—share pathological features with CSDH.²¹^,²²⁾ So far, CEIH after CSDH surgery has not been reported. In our case, the inadvertent introduction of the hematoma outer membrane component into the resection cavity may have contributed to its development, although this remains speculative.

In summary, this case highlights several important clinical implications for the management of malignancy-associated CSDH. First, metastatic involvement of the hematoma outer membrane may be present even in the absence of distinctive radiological findings and should therefore be considered when CSDH occurs in patients with known malignancy, particularly in cases of early recurrence. Second, tumor infiltration may extend beyond the dura mater to involve the hematoma outer membrane, suggesting that resection of both the dural metastatic lesion and the hematoma outer membrane may be considered during craniotomy when technically feasible. Third, the identification of tumor cells in both compartments raises the possibility of more extensive meningeal disease, highlighting the need for careful postoperative surveillance and individualized adjuvant therapy. Recognition of these features may help reduce recurrence and support appropriate clinical decision-making in patients with tumor-related CSDH.

Conclusion

We report a case of rapidly recurrent CSDH after burr-hole drainage, with postoperative imaging revealing dural metastasis of esophageal cancer and pathological examination confirming metastatic involvement of the dura mater and the hematoma outer membrane. To our knowledge, this is the first reported case in which metastatic tumor cells were definitively identified in both sites. In CSDH associated with dural metastasis, metastatic spread to the hematoma outer membrane may also occur, even with inconclusive radiological findings. Therefore, during craniotomy, resection of both the dura and the hematoma outer membrane may be considered, when appropriate, to help reduce the risk of recurrence in patients with underlying malignancy.

Conflicts of Interest

All authors have no conflict of interest.

Informed consent

Informed consent was obtained from the wife of the deceased patient for publication of this case report.

References

Corresponding author

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