A melanocytoma is a rare pigmented tumor that has been described as a variant of the melanocytic nevus [1] and is a derivative of the neural crest. [2] The term "melanocytoma" was introduced by Limas and Tio in 1972. [3] [4]
A melanocytoma is a rare pigmented tumor that has been described as a variant of the melanocytic nevus [1] and is a derivative of the neural crest. [2] The term "melanocytoma" was introduced by Limas and Tio in 1972. [3] [4]
Histologically, the tumor is described by large, uniformly shaped polyhedral nevus cells that are pigmented and closely packed. [5] Typically, it lacks signs of malignancy such as high mitotic rate, necroses or infiltrative growth. [6] Like the malignant melanoma, it shows an immunohistological profile with S-100 protein-, vimentin- and HMB-45-positive tumor cells. [6]
Most commonly the melanocytoma is found on or adjacent to the optic nerve [7] as the optical melanocytoma. The lesion can be found at any age. Location and size could lead to clinical symptoms. While the melanocytoma is generally considered to be a benign tumor, [7] it has a potential for growth, recurrence, and transformation to a malignant melanoma. [5] Because malignant transformation is rare, optical melanocytomas can usually be observed. [1] Thus, in asymptomatic patients, regular observation by fundoscopy is indicated, perhaps supported by ocular ultrasonography. [8] [9] [10]
The meningeal melanocytoma is found on the leptomeninges of the brain, [6] [7] typically in the area of the base of the brain and brain stem, [2] or the spine. [4] [11] Symptoms may be absent or related to growth and location. Like with the optic version, growth, recurrence, and malignant transformation are the main problems. Meningeal melanocytomas represent 0.06-0.1% of brain tumors. [12] In a 2003 review of 95 cases by Rahimi-Movaghar et al, 45 were intracranial (mostly supratentorial) and 50 spinal or along spinal roots. [13] The authors noted that the median age was 40 years for patients with intracranial and 49 for those with spinal tumors. Lesions were more common in women (57.9%). The review showed a recurrence rate of 26.3% and a death rate of 10.5% over 46 months. [13] A 2001 review by Rades et al concluded that complete resection is the best treatment. [14] If resection is incomplete, postoperative radiotherapy should be applied.[ citation needed ]
Pigmented tumors raise the possibility of a malignant melanoma, a condition that may present diagnostic and therapeutic dilemmas. [9] In the differential diagnosis, schwannoma and meningioma with pigmentation are to be considered as well. [11]
Melanocytomas have been described in animals, for instance, dogs and cats. [15] [16]
A melanocytic nevus is a type of melanocytic tumor that contains nevus cells. Some sources equate the term mole with "melanocytic nevus", but there are also sources that equate the term mole with any nevus form.
Nevus is a nonspecific medical term for a visible, circumscribed, chronic lesion of the skin or mucosa. The term originates from nævus, which is Latin for "birthmark"; however, a nevus can be either congenital or acquired. Common terms, including mole, birthmark, and beauty mark, are used to describe nevi, but these terms do not distinguish specific types of nevi from one another.
Meningioma, also known as meningeal tumor, is typically a slow-growing tumor that forms from the meninges, the membranous layers surrounding the brain and spinal cord. Symptoms depend on the location and occur as a result of the tumor pressing on nearby tissue. Many cases never produce symptoms. Occasionally seizures, dementia, trouble talking, vision problems, one sided weakness, or loss of bladder control may occur.
A dysplastic nevus or atypical mole is a nevus (mole) whose appearance is different from that of common moles. In 1992, the NIH recommended that the term "dysplastic nevus" be avoided in favor of the term "atypical mole". An atypical mole may also be referred to as an atypical melanocytic nevus, atypical nevus, B-K mole, Clark's nevus, dysplastic melanocytic nevus, or nevus with architectural disorder.
Dysplastic nevus syndrome, also known as familial atypical multiple mole–melanoma (FAMMM) syndrome, is an inherited cutaneous condition described in certain families, and characterized by unusual nevi and multiple inherited melanomas. First described in 1820, the condition is inherited in an autosomal dominant pattern, and caused by mutations in the CDKN2A gene. In addition to melanoma, individuals with the condition are at increased risk for pancreatic cancer.
Ocular melanosis (OM) is a blue-gray and/or brown lesion of the conjunctiva that can be separated into benign conjunctival epithelial melanosis (BCEM) and primary acquired melanosis (PAM), of which the latter is considered a risk factor for uveal melanoma. The disease is caused by an increase of melanocytes in the iris, choroid, and surrounding structures. Overproduction of pigment by these cells can block the trabecular meshwork through which fluid drains from the eye. The increased fluid in the eye leads to increased pressure, which can lead to glaucoma. In humans, this is sometimes known as pigment dispersion syndrome.
Lentigo maligna is where melanocyte cells have become malignant and grow continuously along the stratum basale of the skin, but have not invaded below the epidermis. Lentigo maligna is not the same as lentigo maligna melanoma, as detailed below. It typically progresses very slowly and can remain in a non-invasive form for years.
The congenital melanocytic nevus is a type of melanocytic nevus found in infants at birth. This type of birthmark occurs in an estimated 1% of infants worldwide; it is located in the area of the head and neck 15% of the time.
Uveal melanoma is a cancer (melanoma) of the eye involving the iris, ciliary body, or choroid. Tumors arise from the pigment cells (melanocytes) that reside within the uvea and give color to the eye. These melanocytes are distinct from the retinal pigment epithelium cells underlying the retina that do not form melanomas. When eye melanoma is spread to distant parts of the body, the five-year survival rate is about 15%.
Blue nevus is a type of melanocytic nevus. The blue colour is caused by the pigment being deeper in the skin than in ordinary nevi. In principle they are harmless but they can sometimes be mimicked by malignant lesions, i.e. some melanomas can look like a blue nevus.
Leptomeningeal cancer is a rare complication of cancer in which the disease spreads from the original tumor site to the meninges surrounding the brain and spinal cord. This leads to an inflammatory response, hence the alternative names neoplastic meningitis (NM), malignant meningitis, or carcinomatous meningitis. The term leptomeningeal describes the thin meninges, the arachnoid and the pia mater, between which the cerebrospinal fluid is located. The disorder was originally reported by Eberth in 1870.
Sebaceous carcinoma, also known as sebaceous gland carcinoma (SGc), sebaceous cell carcinoma, and meibomian gland carcinoma is an uncommon malignant cutaneous tumor. Most are typically about 1.4 cm at presentation. SGc originates from sebaceous glands in the skin and, therefore, may originate anywhere in the body where these glands are found. SGc can be divided into 2 types: periocular and extraocular. The periocular region is rich in sebaceous glands making it a common site of origin. The cause of these lesions in the vast majority of cases is unknown. Occasional cases may be associated with Muir-Torre syndrome. SGc accounts for approximately 0.7% of all skin cancers, and the incidence of SGc is highest in Caucasian, Asian, and Indian populations. Due to the rarity of this tumor and variability in clinical and histological presentation, SGc is often misdiagnosed as an inflammatory condition or a more common neoplasm. SGc is commonly treated with wide local excision or Mohs micrographic surgery, and the relative survival rates at 5 and 10 years are 92.72 and 86.98%, respectively.
A benign melanocytic nevus is a cutaneous condition characterised by well-circumscribed, pigmented, round or ovoid lesions, generally measuring from 2 to 6 mm in diameter. A benign melanocytic nevus may feature hair or pigmentation as well.
Oral pigmentation is asymptomatic and does not usually cause any alteration to the texture or thickness of the affected area. The colour can be uniform or speckled and can appear solitary or as multiple lesions. Depending on the site, depth, and quantity of pigment, the appearance can vary considerably.
Sohan Singh Hayreh is an ophthalmologist, clinical scientist, and professor emeritus of ophthalmology at the University of Iowa. As one of the pioneers in the field of fluorescein angiography, he is generally acknowledge to be a leading authority in vascular diseases of the eye and the optic nerve. For over 60 years, Hayreh has been actively involved in basic, experimental, and clinical research in ophthalmology, publishing over 400 original peer-reviewed articles in various international ophthalmic journals, 6 classical monographs and books in his field of research, and more than 50 chapters in ophthalmic books. He has made many seminal observations dealing with the ocular circulation in health and disease, the optic disc and the optic nerve, retinal and choroidal vascular disorders, glaucomatous optic neuropathy, fundus changes in malignant arterial hypertension, ocular neovascularization, rheumatologic disorders of the eye, and nocturnal arterial hypotension. He is an elected fellow of the National Academy of Medical Sciences.
Diktyoma, or ciliary body medulloepithelioma, or teratoneuroma, is a rare tumor arising from primitive medullary epithelium in the ciliary body of the eye. Almost all diktyomas arise in the ciliary body, although, rarely, they may arise from the optic nerve head or retina.
Neuro-oncology is the study of brain and spinal cord neoplasms, many of which are very dangerous and life-threatening. Among the malignant brain cancers, gliomas of the brainstem and pons, glioblastoma multiforme, and high-grade astrocytoma are among the worst. In these cases, untreated survival usually amounts to only a few months, and survival with current radiation and chemotherapy treatments may extend that time from around a year to a year and a half, possibly two or more, depending on the patient's condition, immune function, treatments used, and the specific type of malignant brain neoplasm. Surgery may in some cases be curative, but, as a general rule, malignant brain cancers tend to regenerate and emerge from remission easily, especially highly malignant cases. In such cases, the goal is to excise as much of the mass and as much of the tumor margin as possible without endangering vital functions or other important cognitive abilities. The Journal of Neuro-Oncology is the longest continuously published journal in the field and serves as a leading reference to those practicing in the area of neuro-oncology.
Vaginal melanoma is a rare malignancy that originates from melanocytes in the vaginal epithelium. It is also known as a melanocytic tumor or as a malignant melanoma. It is aggressive and infrequently cured. The median overall survival is 16 months. Vaginal melanoma accounts 5.5% of all vaginal cancers and only 1% of all melanomas diagnosed in women. Vaginal melanomas are frequently diagnosed in advanced stages of the disease. The prognosis is poor and the most important risk factor is the presence of lymph node metastases.
Michael Belkin is an Israeli academic and researcher working in ophthalmology. Belkin is Professor Emeritus of Ophthalmology at Tel Aviv University. His research brought about advances in glaucoma treatment such as the ExPress glaucoma implant, the Ioptimate CO2 laser glaucoma surgery and a fast, non-contact glaucoma laser treatment.
Alon Harris, MS, PhD, FARVO is an internationally-active clinical scientist, professor of ophthalmology, educator, inventor and researcher in the field of ocular blood flow and its relationship to diseases of the eye. Harris served as the principal or co-principal investigator on more than 60 research grants, published more than 350 peer-reviewed articles, and has written more than 80 books and book chapters. As of 2020, he holds two patents. Harris is the Vice Chair of International Research and Academic Affairs and Director of the Ophthalmic Vascular Diagnostic and Research Program at Icahn School of Medicine at Mount Sinai. Harris has two children - Jonathan and Danielle.