Abducens nerve palsy due to clivus metastasis in a patient with breast carcinoma: A rare case

Abstract

Introduction

Breast cancer, comprising 25 % of all diagnosed cancers, predominantly affects women globally. While bone metastasis is common, occurrences at the clivus or skull base are rarely documented. Treatment varies from surgery in early stages to a multifaceted approach for advanced cases, incorporating chemotherapy, radiotherapy, and surgery based on staging and histology.

Clinical presentation

A 40-year-old female presented with a rapidly enlarging lump in her left breast and diplopia on right gaze. Histology was positive for invasive breast cancer (no special type) and Contrast-Enhanced Computed Tomography demonstrated metastatic deposits in multiple vertebrae and bilateral ilium. Further, magnetic resonance imaging of the brain and orbits revealed metastatic deposits in the clivus which extended up-to medial wall of the cavernous sinus, causing compression of the right abducens nerve. Multidisciplinary Tumor Board review recommended chemoradiotherapy.

Discussion

Metastases from breast cancer can occur locally or to distant sites like lymph nodes, bones, lungs, liver, and brain. Unusual symptoms, such as new-onset diplopia, trigger further investigation. Although bone metastases occur in 50–65 % of cases, clivus metastasis is rare. Treatment aims at extending survival, symptom management, and enhancing quality of life through chemotherapy and radiotherapy. Outcomes hinge on metastatic burden and regional therapy responsiveness. Distant metastases substantially reduce the 5-year survival rate from 80 % to approximately 25 %, but cases often improve with regional interventions.

Conclusion

Although an extremely rare occurrence, clivus metastasis might be considered in patients with a history of malignancy, in particular, breast malignancy, presenting with new-onset sixth nerve palsy.

Highlights

• •Breast cancer rarely metastasizes to the clivus, making it a distinctive and uncommon clinical presentation.
• •New-onset diplopia with a history of breast malignancy, warrants investigation for potential clivus metastasis.
• •Multidisciplinary Tumor Board crucial for tailored plans in metastatic breast cancer & ensure comprehensive evaluation.

1. Introduction

Breast cancer is one of the most common forms of cancer, particularly among the female population, where it is the most prevalent malignancy worldwide (affecting 154 out of 185 countries). While breast cancer can occur in men, it is more than 100 times more common in women [1,2]. A palpable breast lump is the most common presenting symptom followed by nipple abnormalities, breast pain, and breast skin abnormalities [3]. Symptoms of metastasis may vary depending on to the location of spread [4]. Common places of metastasis are bone, liver, lung and brain [5].

Approximately 50 % to 80 % of newly diagnosed cases of breast cancer fall under the category of invasive ductal carcinoma (IDC), while the remaining cases are categorised as invasive lobular carcinoma (ILC) [2].

Treatment strategies are tailored based on factors such as TNM (Tumor- Node- Metastasis) staging, histology, immunology, and the patient's overall fitness level [6]. Surgery is the preferred choice for early stages, while a combination of chemotherapy, radiotherapy, and surgery is often utilised for advanced stages [6]. This case report adheres to the SCARE Criteria to maintain ethical standards and integrity in scientific reporting [24].

2. Case presentation

A 40-year-old female presented with a rapidly enlarging lump in her left breast which was noticed two months ago and had recent onset of diplopia when looking to the right side. The breast lump was clinically malignant looking involving the whole breast, infiltrating skin and deep muscles (Fig. 1). She also had ipsilateral axillary lymph node enlargement on clinical exam and was noted to have evidence of abnormal left level IV cervical and intra mammary lymph nodes on ultrasound. Further cranial nerves examination revealed right sided lateral rectus palsy (Fig. 2), and there was no other neurological weakness.

Fig. 1.

shows left side malignant looking breast lump.

Fig. 2.

Shows right side lateral rectus palsy.

Ultrasound scans of the breast and axilla revealed a BIRADS V lesion on the left side with metastatic axillary lymph node deposits and a normal left breast. A core biopsy of the breast was performed, and the histology results revealed invasive breast carcinoma, No Special Type (NST), Nottingham grade II with lymph vascular infiltration. Immunohistochemistry was positive for ER (estrogen receptor) and PR (progesterone receptor) and negative for HER2 (human epidermal growth factor receptor 2) (Fig. 3).

Fig. 3.

shows cords and nests of tumor cells in a desmoplastic stroma.

Staging contrast-enhanced computerized tomography (CECT) of the chest, abdomen, pelvis and spine revealed multi centric large and small lobulated lesions in the left breast with left axillary lymphadenopathy. There were multiple lytic lesions noted in C2, T11, L2, L3, sacrum, bilateral iliac bones and the right 6th rib (Fig. 4).

Fig. 4.

CECT of the head, neck, chest, abdomen, and pelvis. (A) CT image showing right sided base of the skull lesion (red arrow). (B) CT image showing left breast lesion (red arrow). (C) CT image showing the lytic lesions in T11, L2, and the sacrum. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

A contrast magnetic resonance imaging (MRI) of the brain and orbit was conducted to assess the cause of the diplopia, which showed a well-defined enhancing mass on the right side of the clivus, inferior to the dorsum sellae, measuring 8.6 mm × 10 mm × 10 mm (Fig. 5). This mass projected along the medial wall of the right cavernous sinus and extended further medially into the right sphenoid sinus, compressing the right abducens nerve. The lesion is iso intense in T1 and iso- to- hyper intense in T2 with homogenous contrast enhancement. These findings are consistent with metastasis.

Fig. 5.

(A) MRI showing mass compressing the right abducens nerve; (B) and (C) MRI showing lesion in the clivus extending to the sphenoid sinus.

The patient's case was discussed in a Multidisciplinary Tumor Board review team meeting regarding management. It was decided to initiate chemoradiotherapy for this patient. The patient has now been transferred to a cancer specialty hospital for chemoradiotherapy .

3. Discussion

Breast cancer is the commonest cancer among females in worldwide and Sri Lanka [6,7]. Around 11.7 % with newly identified patients had breast cancer in worldwide and in SriLanka it was 24 % in 2020. It was observed that breast cancer incidence was significantly increased in SriLanka in past years. It has significantly high mortality rate in worldwide [6,7].

Primary breast tumors can exhibit metastatic heterogeneity, spreading to various distant organs. Metastases are classified as local, regional, or distant, depending on their proximity to the original tumor. Localized spread occurs close to the tumor, regional metastases develop in nearby lymph nodes, and distant metastases manifest in remote parts of the body. The most common sites for metastatic breast cancer include the lymph nodes, bones, lungs, skin, liver, and brain [8]. In this case the initial presentation was due to breast lump and diplopia, which is an uncommon presentation and the history, clinical examination and investigations led to the confirmation of the breast cancer and metastases to multiple sites. There are cases reporting prostatic metastasis in clivus causing lateral rectus palsy, but breast metastasis is rarely reported [9].

The abducens nerve has the longest course through the brain [10]. It emerges at the lower border of the pons, above the pyramid of medulla. From here, it passes between the anterior inferior cerebellar artery, travels into the subarachnoid space, and moves along the skull at the clivus. The nerve then travels to the basal skull at the apex of the petrous temporal bone and enters the cavernous sinus. The abducens nerve then passes anteriorly in the sinus, inferolateral to the internal carotid nerve and enters the orbit via the superior orbital fissure to innervate the lateral rectus muscle. This is responsible for abduction of the eye. Abducens nerve palsy leads to lateral rectus palsy, which results in inability to abduct the eye and horizontal diplopia [11].

Common causes for isolated abducens nerve palsy are microvascular aetiologies such as vasculopathic or diabetic, neoplastic or traumatic origin. But bilateral abducens nerve palsies are usually due to intracranial haemorrhage, subdural hematoma or brain stem infraction [12]. Because of its long course through the brain, the abducens nerve is more vulnerable to both traumatic disruption and metastatic disease [13]. Metastasis to the brain from primary carcinomas such as prostate, tonsil, kidney, liver, colon, and lungs have been associated with isolated and multiple cranial nerve palsies [14]. Brainstem metastasis from a breast cancer also associated with isolated abducens nerve palsy [15,16].

Skeletal metastasis of breast cancer is usually multiple and frequently involving more than one bone. Highly vascularised bones including the ribs, vertebral column, proximal ends of long bones and pelvis are more susceptible to metastatic deposits. Bone metastasis to base of the skull, especially clivus is rare in breast cancer [9].

Clival tumors represent only 0.1–0.4 % of all intracranial tumors and clival metastases are an extremely rare subset of clival tumors [17]. In a recent systematic review, by Jozsa and colleagues from cases presented with clivus metastasis showed that prostate, gastrointestinal tract, lung, and kidney are common primary sites of metastatic deposits in the clivus. However, a breast primary as the source of metastasis to the clivus is extremely rare and only few studies reported about this incidence [18].

Approximately 15–30 % of patients with metastatic breast cancer may develop brain metastases, which can significantly impact their quality of life and life expectancy, often leading to significantly shorter survival [19].

Metastatic breast cancer leading to cranial nerve dysfunctions typically arises from bony metastases at the skull base, resulting in nerve compression or infiltration [20], as seen in this case report.

The primary objectives of systemic treatment for metastatic breast cancer (MBC] include extending survival, relieving symptoms, and preserving or enhancing the quality of life. This must be achieved while carefully managing and mitigating the potential toxicities associated with the treatment [21,22,23]. To devise an effective treatment plan for metastatic breast cancer, it is crucial to assess the patient's menopausal status and ascertain the levels of ER, PgR, and HER2 expression [19]. These assessments were done in this patient and the patient was transferred to an oncology unit to initiate chemotherapy and radiotherapy.

4. Conclusion

The incidence and complexity of recurrent or metastatic breast cancer are on the rise. Clivus bone metastasis of breast cancer, while rare, has important implications on patient quality of life and approach to treatment. Recognizing these rare presentations of metastatic breast cancer, such as diplopia, is an important first step in the appropriate investigation and management of such cases. The Multidisciplinary Team (MDT) also plays a pivotal role in patient care by identifying individuals who may benefit from systemic therapy or radiotherapy interventions.

Statement of informed consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in Chief of this journal on request.

Ethical approval

The ethics clearance was not necessary to this study because our Institutional Review Board (IRB) does not require ethical approval for reporting individual cases or case series.

Funding

None.

Author contribution

Study concept – SR, JSN

Data collection – JSN

Interpretation - SR , JSN, GN

Manuscript preparing – SR, JSN, GN

Guarantor

JUde Selvakumar Nilojan.

Declaration of competing interest

There is no conflict of interest between the authors as everybody is aware of the work and participated actively and equally.