Amelanotic melanoma of the lung and brain with fenestrated intrinsic tumor capillaries

Intracranial amelanotic melanoma: a case report with literature review

Background

The incidence of primary central nervous system (CNS) melanocytic neoplasms is relatively low comparing to systemic ones. The performance of the tumor is variable. With poor clinical experience, the diagnosis and treatment of such tumors present to be a challenge. Amelanotic melanoma is an especially rare subtype. Only several cases have been reported.

Case presentation

We report a case of intracranial amelanotic melanoma. Preoperative assessment revealed progressive right frontal mass. The patient underwent tumor resection. The pathologic analysis reported amelanotic melanoma of intermediate grade. The further examination of the whole brain and body was negative. The familial history was also negative. The patient recovered uneventfully and went on for radiotherapy and chemotherapy. After a follow-up period of 5 months, the patient was tumor-free.

Conclusions

This is the second report about primary CNS amelanotic melanoma. We summarized characteristics of the primary CNS melanocytic lesions and amelanotic melanoma with review of the literature and review of cases of our department.

Endothelial stomatal and fenestral diaphragms in normal vessels and angiogenesis

Vascular endothelium lines the entire cardiovascular system where performs a series of vital functions including the control of microvascular permeability, coagulation inflammation, vascular tone as well as the formation of new vessels via vasculogenesis and angiogenesis in normal and disease states. Normal endothelium consists of heterogeneous populations of cells differentiated according to the vascular bed and segment of the vascular tree where they occur. One of the cardinal features is the expression of specific subcellular structures such as plas-malemmal vesicles or caveolae, transendothelial channels, vesiculo-vacuolar organelles, endothelial pockets and fenestrae, whose presence define several endothelial morphological types. A less explored observation is the differential expression of such structures in diverse settings of angiogenesis. This review will focus on the latest developments on the components, structure and function of these specific endothelial structures in normal endothelium as well as in diverse settings of angiogenesis.