A rare case of intracranial metastatic amelanotic melanoma with cyst

Abstract

A rare case of intracranial metastatic amelanotic melanoma with cyst is presented. The patient was a 51 year old woman with a malignant melanoma arising on her right chest. Two years after a wide excision, skin and brain metastasis occurred. Brain magnetic resonance images demonstrated a tumour with a cyst in the left occipital lobe. Because the tumour showed low intensity on T1 weighted images and high intensity on T2 weighted images, the metastatic melanoma was identified as an amelanotic melanoma. Intracranial amelanotic melanoma is very rare, and there have been few reports of melanoma with cyst.

Figure 1

Preoperative view: the nodule was flat, irregular in shape, and 1.5 × 1.3 × 2 cm in size. An excisional biopsy with a 5 mm normal skin margin was performed to decide on the specific treatment plan.

Figure 2

Pathological findings: the tumour cells had clearly invaded between the collagen bundles of the reticular dermis with nest formation (haematoxylin and eosin stain; original magnification, ×2).

Figure 3

Pathological findings (haematoxylin and eosin stain; original magnification, ×20).

Figure 4

(A) A brain computed tomography (CT) image at one year after a wide excision. There are no specific findings. (B) A brain CT image at two years after a wide excision. The image shows a high density area in the left occipital lobe.

Figure 5

Brain magnetic resonance images at two years after a wide excision. (A) T1 weighted image (T1WI): axial view; (B) T2 weighted image (T2WI): axial view; (C) enhanced T1WI: axial view; (D) fluid attenuated inversion recovery: axial view; (E) enhanced T1WI: coronal view.

Figure 6

Brain magnetic resonance images at two years and one month after a wide excision. (A) T1 weighted image (T1WI): axial view; (B) T2 weighted image (T2WI): axial view; (C) enhanced T1WI: axial view; (D) fluid attenuated inversion recovery: axial view; (E) enhanced T1WI: coronal view.