Miller Brandon A, Tanaka Tomoko, Ioachimescu Adriana G, Vincentelli Cristina, Appin Christina L, Oyesiku Nelson M
Emory University School of Medicine, Atlanta, GA, USA.
J Investig Med High Impact Case Rep. 2013 Jun 17;1(2):2324709613494008. doi: 10.1177/2324709613494008. eCollection 2013 Apr-Jun.
Silent adrenocorticotrophic pituitary adenomas are nonfunctioning pituitary adenomas that express adrenocorticotrophic hormone (ACTH) but do not cause the clinical or laboratory features of hypercortisolemia. Primary central nervous system (CNS) melanoma is well documented, but rarely originates in the sellar region or pituitary gland. Here we report transformation of an aggressive silent adrenocorticotrophic pituitary adenoma that transformed into CNS melanoma and review other presentations of pituitary melanoma. A 37-year-old woman initially presented with apoplexy and an invasive nonfunctioning pituitary macroadenoma for which she underwent transphenoidal surgery. The patient underwent 3 subsequent surgeries as the tumor continued to progress. Pathology from the first 3 operations showed pituitary adenoma or carcinoma. Pathology from the final surgery showed melanoma and the magnetic resonance imaging characteristics of the tumor had changed to become consistent with CNS melanoma. Dermatologic and ophthalmologic examinations did not identify cutaneous or ocular melanoma. The patient's disease progressed despite aggressive surgical, medical and radiologic treatment. To our knowledge, this is the first report demonstrating transformation of a primary pituitary tumor into melanoma. The mechanism of tumor transformation is unclear, but it is possible that a mutation in the original ACTH-producing tumor lead to increased cleavage of pro-opiomelanocortin or ACTH into α-melanocyte-stimulating hormone, which in turn stimulated the expression of microopthalmia transcription factor, leading to melanocytic phenotype transformation.
沉默型促肾上腺皮质激素垂体腺瘤是一种无功能垂体腺瘤，它表达促肾上腺皮质激素（ACTH），但不会引起高皮质醇血症的临床或实验室特征。原发性中枢神经系统（CNS）黑色素瘤已有充分记载，但很少起源于鞍区或垂体。在此，我们报告一例侵袭性沉默型促肾上腺皮质激素垂体腺瘤转变为CNS黑色素瘤的病例，并回顾垂体黑色素瘤的其他表现形式。一名37岁女性最初因卒中及侵袭性无功能垂体大腺瘤就诊，为此她接受了经蝶窦手术。由于肿瘤持续进展，该患者随后又接受了3次手术。前3次手术的病理显示为垂体腺瘤或癌。最后一次手术的病理显示为黑色素瘤，且肿瘤的磁共振成像特征已转变为与CNS黑色素瘤一致。皮肤科和眼科检查未发现皮肤或眼部黑色素瘤。尽管进行了积极的手术、药物和放射治疗，患者的病情仍进展。据我们所知，这是首例证明原发性垂体肿瘤转变为黑色素瘤的报告。肿瘤转变的机制尚不清楚，但有可能最初产生ACTH的肿瘤发生突变，导致阿片促黑激素皮质素原或ACTH更多地裂解为α-黑素细胞刺激素，进而刺激小眼畸形转录因子的表达，导致黑素细胞表型转变。
