Melanocytic tumors of uncertain malignant potential (MELTUMP) are

melanocytic Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), the inner ear, vaginal epithelium, meninges, bones, and heart. ...

lesion A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals. Types There is no designated classifi ...

s in the

dermis The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided i ...

that cannot be classified by

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines * Morphology (archaeology), study of the shapes or forms of artifacts * Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies ...

as either benign

naevi Nevus (plural nevi) 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 (present at bir ...

(moles) or malignant

melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...

s because the mass shows features of both. Several lesion types may be classified as MELTUMPs: these include atypical melanocytic proliferations with features that may overlap with atypical Spitz naevi/tumors, dysplastic naevi, pigmented epithelioid melanocytoma, deep penetrating naevi, congenital naevi, cellular nodules in congenital naevi, possible naevoid melanomas, and cellular blue naevi. A related category of melanocytic proliferation is ''superficial atypical melanocytic proliferations of uncertain significance'' (SAMPUS). This category, unlike MELTUMP, which implies as yet undetermined potential for metastases even after complete excision, signifies lesions without metastatic potential at time of excision but with potential to progress upon incomplete excision. The SAMPUS category includes certain atypical junctional melanocytic proliferations and proliferations in both the

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...

and

papillary dermis The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided in ...

that are not accompanied by intradermal tumorigenic architecture or cell

mitosis In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is mainta ...

See also

References

Further reading