Orbital metastasis of renal cell carcinoma masquerading as thyroid ophthalmopathy

Abstract

Renal cell carcinoma (RCC) is the most common kidney malignancy in adults. However, its presentation with orbital metastasis as the first clinical manifestation is extremely rare and can mimic several other conditions. We report the case of a 72-year-old woman with a history of hyperthyroidism, who presented with symptoms resembling thyroid ophthalmopathy. However, magnetic resonance imaging (MRI) of the orbit revealed orbital metastasis. To find the primary tumor, a surveillance computed tomography (CT) was done which showed a mass in the left kidney suggestive of RCC. Histopathological analysis of the mass confirmed clear cell RCC. Early identification of orbital metastases in RCC is crucial, as it may indicate advanced disease. Misdiagnosis due to similarities with other orbital conditions can lead to delayed treatment and suboptimal outcomes. This case highlights the pivotal role of radiological imaging in guiding the diagnosis and management of orbital metastases from RCC.

Keywords: Clear cell renal cell carcinoma; Magnetic resonance imaging (MRI); Orbital metastasis; Palliative radiotherapy; Renal cell carcinoma; Thyroid ophthalmopathy.

Fig. 1

Contrast enhanced magnetic resonance imaging (MRI) of the orbit. (A) Coronal and (B) Axial T1 post-contrast images showing a hyperintense lesion with soft tissue component measuring 3.5 × 3 × 3.5 cm located in the right orbit (yellow arrow). It extends into intraconal region involving right temporalis muscle with lytic destruction of right greater wing of sphenoid and orbital process of frontal bone.

Fig. 2

Contrast enhanced computed tomography (CT) of thorax and abdomen. (A) Coronal and (B) Axial images showing a large heterogeneously enhancing soft tissue mass lesion measuring 16 × 13.1 × 12.1 cm arising from the upper pole of the left kidney (yellow arrow). Well circumscribed lytic lesion measuring 6.6 × 4.5 × 4.7 cm arising from the lateral aspect of right 4th rib (red arrow). Multiple enhancing mass lesions in the liver parenchyma (blue arrow).

Fig. 3

Histopathological examination of tru-cut biopsy specimen of the left kidney mass with hematoxylin and eosin staining showing tumor cells with abundant clear cytoplasm that are vacuolated with indistinct cell borders pathognomonic for clear cell renal cell carcinoma.