Adult T-cell leukemia/lymphoma
Angiocentric lymphoma (extranodal natural killer cell lymphoma, nasal-type NK lymphoma, NK/T-cell lymphoma, polymorphic/malignant midline reticulosis)
Angioimmunoblastic T-cell lymphoma (angioimmunoblastic lymphadenopathy with dysproteinemia)
Blastic NK-cell lymphoma
CD30+ cutaneous T-cell lymphoma (primary cutaneous anaplastic large cell lymphoma)
Cutaneous lymphoid hyperplasia (borrelial lymphocytoma, lymphadenosis benigna cutis, lymphocytoma cutis, pseudolymphoma, pseudolymphoma of Spiegler and Fendt, sarcoidosis of Spiegler and Fendt, Spiegler–Fendt lymphoid hyperplasia, Spiegler–Fendt sarcoid) 
Cutaneous lymphoid hyperplasia with bandlike and perivascular patterns
Cutaneous lymphoid hyperplasia with nodular pattern (nodular pattern of cutaneous lymphoid hyperplasia)
Diffuse large B-cell lymphoma (primary cutaneous large B-cell lymphoma)
Granulocytic sarcoma (chloroma, myeloid sarcoma)
Granulomatous slack skin
Hairy-cell leukemia
Hodgkins disease
Ichthyosis acquisita (acquired ichthyosis)
IgG4-related skin disease
Intravascular large B-cell lymphoma (angiotropic large cell lymphoma, intralymphatic lymphomatosis, intravascular lymphomatosis, malignant angioendotheliomatosis)
Jessner lymphocytic infiltrate of the skin (benign lymphocytic infiltration of the skin, Jessner lymphocytic infiltration of the skin, Jessner–Kanof lymphocytic infiltration of the skin, lymphocytic infiltrate of Jessner)
Kikuchis disease (histiocytic necrotizing lymphadenitis)
Large plaque parapsoriasis (parapsoriasis en plaques)
Lennert lymphoma (lymphoepitheliod lymphoma)
Leukemia cutis
Lymphoma cutis
Lymphomatoid granulomatosis
Lymphomatoid papulosis
Malignant histiocytosis (histiocytic medullary reticulosis)
Marginal zone B-cell lymphoma
Mucosa-associated lymphoid tissue lymphoma
Mycosis fungoides
Non-mycosis fungoides CD30− cutaneous large T-cell lymphoma
Nonspecific cutaneous conditions associated with leukemia (leukemid)
Pagetoid reticulosis (acral mycoses fungoides, localized epidermotropic reticulosis, mycosis fungoides palmaris et plantaris, unilesional mycosis fungoides, Woringer–Kolopp disease)
Pityriasis lichenoides chronica (chronic guttate parapsoriasis, chronic pityriasis lichenoides, dermatitis psoriasiformis nodularis, parapsoriasis chronica, parapsoriasis lichenoides chronica)
Pityriasis lichenoides et varioliformis acuta (acute guttate parapsoriasis, acute parapsoriasis, acute pityriasis lichenoides, Mucha–Habermann disease, parapsoriasis acuta, parapsoriasis lichenoides et varioliformis acuta, parapsoriasis varioliformis)
Plasmacytoma 
Plasmacytosis
Pleomorphic T-cell lymphoma (non-mycosis fungoides CD30− pleomorphic small/medium-sized cutaneous T-cell lymphoma)
Polycythemia vera (erythremia)
Primary cutaneous follicular lymphoma (follicular center cell lymphoma, follicular center lymphoma)
Primary cutaneous immunocytoma
Primary cutaneous marginal zone lymphoma
Retiform parapsoriasis
Secondary cutaneous CD30+ large cell lymphoma
Sézary syndrome
Sinus histiocytosis with massive lymphadenopathy (Rosai–Dorfman disease)
Subcutaneous T-cell lymphoma (panniculitis-like T-cell lymphoma)
Vesiculopustular eruption and leukemoid reaction in Down syndrome

Melanocytic nevi and neoplasms
Melanocytic nevi and neoplasms are caused by either a proliferation of (1) melanocytes, or (2) nevus cells, a form of melanocyte that lack dendritic processes.
Popliteal pterygium syndrome (PPS) is an inherited condition affecting the face, limbs, and genitalia. The syndrome goes by a number of names including the popliteal web syndrome and, more inclusively, the facio-genito-popliteal syndrome. The term PPS was coined by Gorlin et al. in 1968 on the basis of the most unusual anomaly, the popliteal pterygium (a web behind the knee). Symptoms and signs
Clinical expressions of PPS are highly variable, but include the following:
Limb findings: an extensive web running from behind the knee down to the heel (90%), malformed toenails, and webbed toes. Facial findings: cleft palate with or without cleft lip (75%), pits in the lower lip (40%), fibrous bands in the mouth known as syngnathia (25%), and tissue connecting the upper and lower eyelids
Genital findings (50%): hypoplasia of the labia majora, malformation of the scrotum, and cryptorchidism. Genetics
The genetic locus for PPS was localized to chromosome 1 in 1999. The disorder is inherited in an autosomal dominant manner and is due to mutation of the IRF6 gene. Most reported cases are sporadic; advanced parental age is found in a number of these cases, suggesting new mutations.The term PPS has also been used for two rare autosomal recessively inherited conditions: Lethal PPS and PPS with Ectodermal Dysplasia. Although both conditions feature a cleft lip/palate, syngnathia, and popliteal pterygium, they are clinically distinguishable from the autosomal dominant case.