Closely related to the concept of symmetry is the presence of good circumscription, which is perhaps best expressed in practical terms as readily identifiable edges to the intraepidermal
In fact, at the onset, M is characterized by a non-tumorigenic radial growth phase (RGP), inside the epidermis (intraepidermal
) or within the papillary dermis (microinvasive), devoid of metastatic potential, which may be followed, early or late, by a tumorigenic vertical growth phase (VGP), with deeper extension in the dermis or beyond, nodular confluence, mitotic activity, and metastatic capacity (Table 1).
However, according to some authors, large numbers of neutrophils in parakeratosis in the viable epidermis or neutrophils forming intraepidermal
collections, as well as more numerous extravasated erythrocytes in the epidermis and necrosis more emphasized in the upper part of the epidermis, are features more common in HFMD (24), which was also present in our case to some extent.
Pedunculated melanomas present as exophytic masses, with or without pigmentation and/or ulceration, and are classically defined as tumors with greater than 50% to 100% of their area above the epidermis, suspended from a free stalk, and lateral dissemination encompassing less than three intraepidermal
crests.2 Pedunculated melanomas have often been grouped with other exophytic melanomas, not suspended from a free stalk, bringing controversy regarding staging and clinical management of such tumors.
Exfoliative toxins (exfoliative toxins A and B) cause intraepidermal
separation in the stratum granulosum and lead to a condition that is characterized by widespread epidermolysis all over the body and bullae with a positive Nikolsky's sign.
Tubule and neurofilament immunoreactivity in human hairy skin: Markers for intraepidermal
There may be spongiosis and intraepidermal
The integument had scattered dermal heterophilic, lymphoplasmacytic aggregates, with serocellular intraepidermal
or superficial heterophilic crusting.
This differential diagnosis is specially considered when, in an adult, a tumor is localized in the lower extremities; it is dermal based without an intraepidermal
component, the patient has no previous history of malignant melanoma, and the tumor expresses S-100 protein.
Histopathological study showed pseudoepitheliomatous hyperplasia of epidermis with eosinophilic spongiosis and intraepidermal
Skin punch biopsy revealed an ulcerative lesion with a fibrinous cap and spongiotic vesicles (Figure 4) with marked eosinophilic exocytosis associated with dyskeratotic keratinocytes and eosinophilic intraepidermal
microabscess formation (Figure 5).
Granulysin is produced by intraepidermal
natural killer (NK) cells and cytotoxic [CD8.sup.+] T-cells in the early phase of SJS/TEN .