A Man in His Mid‐70s With a Sellar Mass

Abstract

Metastatic melanoma to a pituitary oncocytoma is a very rare condition. A 76-year-old man was presented with progressive visual disturbance and falling down with initial loss of consciousness 2 days before admission. He had a subungual acral lentiginous melanoma (T3N1M0) with gangrenous change of left big toe, treated by amputation 15 months ago. Computed tomography and MR imaging demonstrated masses involving inguina, mediastinum and left renal hilum and dumb-bell shaped hyperdense mass, approximately 6.2 x 3.7 mm, that involved pituitary fossa and suprasellar region with adjacent bony destruction. He underwent surgical resection of the tumor. Microscopically, the tumor revealed an admixture of pituitary adenoma and invasive metastatic melanoma with fragments containing both populations in juxtaposition. The adenoma was negative for melanoma markers and pituitary hormone markers. The melanoma was positive for S-100 protein and BMB-45. Ultrastructure of the adenoma revealed abundant mitochondria and sparse secretory granules. The diagnosis was metastatic melanoma to a pituitary oncocytoma. The current literature on metastatic tumors to pituitary adenoma is reviewed.

Progressive visual disturbance and enlarging prolactinoma caused by melanoma metastasis

“…Because of this, efficiency of metastases is not high. [11] To date, there is only 1 case reported regarding melanoma metastasis to pituitary adenoma (Table 1) [12] and 26 cases of different tumors metastatic to pituitary adenoma (Table 2). [13–34] Tumor metastasis to tumor is rare in clinical practice and much more intractable, because it is usually accompanied by multiple metastases.…”

Diagnostic and prognostic biomarkers of a sellar melanocytic tumor mimicking pituitary adenoma: Case report and literature review

“…Many melanocytes can be found around the floor of the sella, predominately in the meningeal lining, the ventrolateral regions of the medulla oblongata, and around the spinal cord [9,15,17]. Metastatic melanomas represent spread from a primary tumor developing in the skin, or less commonly the lungs, gastrointestinal tract, retina, or other distant sites [4,6,18,19]. Metastatic melanoma usually grows rapidly and has a poor prognosis.…”

Melanoma of the sellar region

“…To our knowledge there have been only 30 patients reported previ- ously. [4][5][6][7][8][9][10][11] The majority of these were autopsy findings in the context of disseminated spread; however, there are seven patients where clinical symptoms associated with the pituitary metastasis are described. 3,4,6,8 There have also been occasional reports of melanomas originating unequivocally from the leptomeninges of the sellar region.…”

“…[4][5][6][7][8][9][10][11] The majority of these were autopsy findings in the context of disseminated spread; however, there are seven patients where clinical symptoms associated with the pituitary metastasis are described. 3,4,6,8 There have also been occasional reports of melanomas originating unequivocally from the leptomeninges of the sellar region. [9][10][11][12] In the present patient we were unable to identify a primary site of origin of the melanoma despite detailed dermatological and radiological review.…”

“…Average survival from the published clinical cases following diagnosis and treatment is approximately 4 months. 3,4,6,8 Trans sphenoidal surgery for establishing the histological diagnosis and tumour debulking is performed in most instances, with post-operative adjuvant radio -and/or chemotherapy. Surgery can also disseminate the disease if the arachnoid layer is breached during the trans sphenoidal approach.…”