Spitz tumors represent a heterogeneous group of challenging melanocytic neoplasms, displaying a range of biological behaviors, spanning from benign lesions, Spitz nevi (SN) to Spitz melanomas (SM), with intermediate lesions in between known as atypical Spitz tumors (AST). They are histologically characterized by large epithelioid and/or spindled melanocytes arranged in fascicles or nests, often associated with characteristic epidermal hyperplasia and fibrovascular stromal changes. In the last decade, the detection of mutually exclusive structural rearrangements involving receptor tyrosine kinases ROS1, ALK, NTRK1, NTRK2, NTRK3, RET, MET, serine threonine kinases BRAF and MAP3K8, or HRAS mutation, led to a clinical, morphological and molecular based classification of Spitz tumors. The recognition of some reproducible histological features can help dermatopathologist in assessing these lesions and can provide clues to predict the underlying molecular driver. In this review, we will focus on clinical and morphological findings in molecular Spitz tumor subgroups.

Melanocytic lesions are instable tumors, the genome of which and its changes determinate their morphology and biological properties. Intermediate lesions share histomorphological features of both, nevi and melanoma. Melanocytomas represent a group of them separated on the basis of recent molecular-biological studies. The article summarizes benign, intermediate, malignant and combined melanocytic skin lesions and offers practical recommendations for diagnosis.

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Meningeal melanocytoma is a rare benign tumor, most frequently located in the posterior fossa and spinal canal. The aim of this study was to investigate the clinical manifestations, radiological features, management, and follow-up data of spinal meningeal melanocytomas. We present the clinical data and long-term outcomes from a consecutive surgical series of 16 patients with pathologically diagnosed spinal meningeal melanocytomas. All of the patients underwent surgical resection. Pre and postoperative MRI was performed. Follow-up data and neurological functional assessment is presented and discussed. The mean age at diagnosis was 42.0 years, with a significant male predominance. The primary clinical symptoms were weakness or numbness of the extremities. The appearance of melanocytoma on MRI is typically isointense to hyperintense on T1-weighted images, hypointense on T2-weighted images, and contrast enhancement tends to be remarkable and homogeneous. In most cases, gross total resection is achievable; however, in rare cases with dumbbell-shaped tumors involving the extraspinal region, a staging operation and subtotal resection should be attempted. During a mean follow-up period of 58.1 months, the symptoms were completely relieved in all the patients, and no tumor progression or recurrence was noted. Melanocytic tumors of the central nervous system have a typical appearance on MRI scans, varying with the content and distribution of melanin. However, the differential diagnosis between malignant melanoma and melanocytoma still depends on pathological criteria. Spinal meningeal melanocytoma has a benign course, and it is amenable for gross total resection. The outcome is favorable following complete resection.