Melanocytoma
A melanocytoma is a rare pigmented tumor that has been described as a variant of the melanocytic nevus[1] and is derived from the neural crest.[2] The term "melanocytoma" was introduced by Limas and Tio in 1972.[3][4]
Histology
[edit]Histologically, the tumor is characterized by large, uniformly shaped polyhedral nevus cells that are pigmented and closely packed.[5] Typically, it lacks signs of malignancy, such as a high mitotic rate, necrosis, or infiltrative growth.[6] Similar to malignant melanoma, it exhibits an immunohistochemical profile with S-100 protein-, vimentin-, and HMB-45-positive tumor cells.[6]
Optic melanocytoma
[edit]A melanocytoma most commonly occurs on or adjacent to the optic nerve[7] as an optic melanocytoma. The lesion can be found at any age, and its location and size may lead to clinical symptoms. While melanocytomas are generally considered to be benign tumors,[7] they have the potential for growth, recurrence, and transformation into malignant melanoma.[5] Because malignant transformation is rare, optic melanocytomas can usually be managed with observation.[1] Therefore, in asymptomatic patients, regular monitoring via fundoscopy is recommended, potentially supported by ocular ultrasonography.[8][9][10]
Meningeal melanocytoma
[edit]A meningeal melanocytoma is a rare, pigmented tumor found on the leptomeninges of the brain,[6][7] typically in the area of the base of the brain and brainstem,[2] or the spine.[4][11] Symptoms may be absent or related to the tumor's growth and location. Similar to optic melanocytomas, the main concerns include growth, recurrence, and malignant transformation. Meningeal melanocytomas account for 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 were spinal or located along spinal roots.[13] The authors noted that the median age was 40 years for patients with intracranial tumors and 49 years for those with spinal tumors. The lesions were more common in women (57.9%). The review reported a recurrence rate of 26.3% and a mortality rate of 10.5% over a 46-month period.[13]
A 2001 review by Rades et al. concluded that complete resection is the best treatment option.[14] If resection is incomplete, postoperative radiotherapy is recommended.[citation needed]
Differential diagnosis
[edit]Pigmented tumors can raise concerns about the possibility of a malignant melanoma, a condition that may present both diagnostic and therapeutic challenges.[9] In the differential diagnosis, other conditions such as schwannoma and meningioma with pigmentation should also be considered.[11]
Veterinary medicine
[edit]Melanocytomas have been described in animals, including dogs and cats.[15][16]
See also
[edit]References
[edit]- ^ a b Shields, Jerry A.; Demirci, Hakan; Mashayekhi, Arman; Eagle, Ralph C.; Shields, Carol L. (2006). "Melanocytoma of the Optic Disk: A Review". Survey of Ophthalmology. 51 (2): 93–104. doi:10.1016/j.survophthal.2005.12.011. ISSN 0039-6257. PMID 16500211.
- ^ a b Sethi, Divya; Duhan, Amrita; Sen, Rajeev; Goyal, Vandana; Modi, Shilpi (2011). "Spinal meningeal melanocytoma". Asian Journal of Neurosurgery. 6 (2): 110–2. doi:10.4103/1793-5482.92176. ISSN 1793-5482. PMC 3277064. PMID 22347335.
- ^ Limas C, Tio FO (1972). "Meningeal melanocytoma ("melanotic meningioma"). Its melanocytic origin as revealed by electron microscopy". Cancer. 30 (5): 1286–94. doi:10.1002/1097-0142(197211)30:5<1286::aid-cncr2820300522>3.0.co;2-v. PMID 4343293.
- ^ a b Shanthi, Vissa; Ramakrishna, BA; Bheemaraju, Vydehi Venkata; Rao, Nandam Mohan; Athota, Venkata Ramana Murthy (2010). "Spinal meningeal melanocytoma: A rare meningeal tumor". Annals of Indian Academy of Neurology. 13 (4): 308–10. doi:10.4103/0972-2327.74192. ISSN 0972-2327. PMC 3021939. PMID 21264144.
- ^ a b Mohmad, Zalilawati; Aik Kah, Tan; Chui Yong, Ku; Wan Abdul Halim, Wan Haslina; Kong Yong, Then (2011). "Melanocytoma of the optic nerve head - a diagnostic dilemma". Clinics and Practice. 1 (3): 60. doi:10.4081/cp.2011.e60. ISSN 2039-7283. PMC 3981369. PMID 24765321.
- ^ a b c Schindler CU, Kuchelmeister K, Richter HP, Schachenmayr W (1998). "Das meningeale Melanozytom". Pathologe. 19 (4): 325–9. doi:10.1007/s002920050292. PMID 9746920. S2CID 41524594.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ a b c Reidy, James J.; Apple, David J.; Steinmetz, Robert L.; Craythorn, Judy M.; Loftfield, Katherine; Gieser, Stephen C.; Brady, Steven E. (1985). "Melanocytoma: Nomenclature, pathogenesis, natural history and treatment". Survey of Ophthalmology. 29 (5): 319–327. doi:10.1016/0039-6257(85)90107-9. ISSN 0039-6257. PMID 3992470.
- ^ P. M. Sharma u. a.: Malignant transformation of optic disc melanocytoma? A clinical dilemma at presentation with a review of the literature. In: Ophthalmologica 216, 2002, S. 292–295. PMID 12207136 (Review).
- ^ a b Murray, Timothy G. (2010). "Clinical imaging and high-resolution ultrasonography in melanocytoma management". Clinical Ophthalmology. 4: 855–859. doi:10.2147/OPTH.S11891. ISSN 1177-5483. PMC 2921292. PMID 20714362.
- ^ Lisker-Cervantes, Andrés; Ancona-Lezama, David Arturo; Arroyo-Garza, Luis Javier; Martinez, Jaime D.; Barreiro, Roberta Gomez Diaz; Valdepeña-López-Velarde, Victor Daniel; Morales-Canton, Virgilio; Moragrega-Adame, Eduardo (2017). "Ocular ultrasound findings in optic disk melanocytoma". Revista Mexicana de Oftalmología. 91 (6): 316–320. doi:10.1016/j.mexoft.2017.03.003. ISSN 0187-4519.
- ^ a b Wang, F.; Li, X.; Chen, L.; Pu, X. (2007). "Malignant transformation of spinal meningeal melanocytoma. Case report and review of the literature". Journal of Neurosurgery: Spine. 6 (5): 451–4. doi:10.3171/spi.2007.6.5.451. PMID 17542513.
- ^ Elazim, Ahmed Abd; Elbadry, Rasha; Mohamed, Kazim; Issa, Mamdouh; Ayyad, Ali (2018). "Primary meningeal melanocytoma of the cerebellopontine angle associated with ipsilateral nevus of Ota: A case report". Surgical Neurology International. 9 (1): 245. doi:10.4103/sni.sni_235_18. ISSN 2152-7806. PMC 6293867. PMID 30613434.
- ^ a b Rahimi-Movaghar, Vafa; Karimi, Mehrbod (2003). "Meningeal melanocytoma of the brain and oculodermal melanocytosis (nevus of Ota): case report and literature review". Surgical Neurology. 59 (3): 200–210. doi:10.1016/S0090-3019(02)01052-2. ISSN 0090-3019. PMID 12681556.
- ^ Rades, Dirk; Heidenreich, Fedor; Tatagiba, Marcos; Brandis, Almuth; Karstens, Johann Hinrich (2001). "Therapeutic options for meningeal melanocytoma". Journal of Neurosurgery: Spine. 95 (2): 225–231. doi:10.3171/spi.2001.95.2.0225. ISSN 1547-5654. PMID 11599841.
- ^ Martens, A. L. (2007). "Unusual presentation of an anterior uveal melanocytoma in a 3-year-old poodle". The Canadian Veterinary Journal. 48 (7): 748–750. PMC 1899854. PMID 17824163.
- ^ Wilcock B, Dubielzig R.R., Render J.A. Histological Classification of Ocular and Otic Tumors of Domestic Animals. In: Schulman F.Y., editor. WHO International Histological Classification of Tumors of Domestic Animals. IX. Armed Forces Institute of Pathology; Washington, D.C.: 2002.