melanomas lack some or all pigment and can be extremely difficult to identify.
The ICD-O classification includes further morphological codes, such as balloon cell M, regressing M, amelanotic
M, M in junctional nevus, M in precancerous melanosis, desmoplastic M, neurotropic M, mucosal lentiginous M, M in giant pigmented nevus/congenital melanocytic nevus, mixed epithelioid and spindle cell M, epithelioid cell M, spindle cell M (not otherwise specified), spindle cell M (type A), spindle cell M (type B), and malignant blue nevus (3).
(6,16) Importantly, these observations allow for meaningful comparison with potential metastases, which are often amelanotic
 Virtually amelanotic
examples may be encountered but are exceptional.
Keywords: Pedunculated melanoma, amelanotic
Immunohistochemical staining for S100 protein in the diagnosis of canine amelanotic
However, the best treatment modality is excision.[5,9,10] Amelanotic
melanoma and SCC should be considered for the differential diagnosis.
A modified ABCDE for pediatric melanoma has been proposed: amelanotic
, bump/bleeding, color uniformity, diameter variability, de novo, and evolution.
melanoma is a rare form of the urethral MM, and often resembles urethral caruncle.
(1,2,3) It manifests with a painless melanotic or amelanotic
mass on the ocular surface and is usually accompanied by a persistent dilated feeder blood vessel.
Mortimer, "Aggressive amelanotic
lentigo maligna," British Journal of Dermatology, vol.
examined ALP immunoreactivity of 61 cytopathology samples from canine, consisting of 33 OSAs, 4 chondrosarcomas, 4 synovial sarcomas, 2 fibrosarcoma, 9 soft tissue sarcomas, 2 plasma cell tumours, 2 lymphomas, 2 amelanotic
melanomas, 2 mast cell tumours, and 1 multilobular tumour (MLT) of bone, which showed sensitivity and specificity of 100% and 89% .