S4C20P12-1: Lesions of PLVA sometimes show a high component of transformed T lymphocytes, as seen in this example. Lymphocytes and histiocytes intermingle among keratinocytes in the epidermal domain. There are small lytic defects. The lymphoid cells have enlarged, irregular nuclei, and dense chromatin patterns. Patterns of this type are ambiguous; they qualify as mild to moderate T cell dysplasia of indeterminate type. Patterns of this type are responsible for the confusion between some lesions of PLVA and lesions of lymphomatoid papulosis. It has even been proposed that the two are sequentially related and that an epidermal infiltrate containing atypical cells of the type seen in this field, in a proportion greater than 10%, is evidence in favor of a diagnosis of lymphomatoid papulosis. If some lesions in the setting of PLVA also qualify as lymphomatoid papulosis, then it would seem appropriate to qualify lymphomatoid papulosis as a heterogeneous category, with some examples being expressions of progressions in the more specific category of PLVA (i.e., atypical PLVA). Patterns in the dermis are generally a great aid in recognizing the most classic variant of lymphomatoid papulosis.

S4C20P12-3: In a selected area at a higher magnification, green arrows identify atypical (transformed) T lymphocytes in the epidermal domain. There are two apoptotic foci in patterns that qualify as “satellite cell necrosis.” The dermal infiltrates are mild and non-specific. A lesion of this type is pityriasic, but ambiguous in type. Clinicopathologic correlations would be some aid in classification. The lesion additionally qualifies as a mild T cell dysplasia of indeterminate type. This qualification identifies the lesion as showing cytologic atypia (for those who can recognize cytologic atypia), but does not identify the process as a convincing progressive T cell dysplasia. Additional studies and follow-up are indicated.

S4C20P12-4: In yet another selected field from a lesion of PLVA, lymphoid cells of the epidermal infiltrates show variations in nuclear size and nuclear outlines; some of the cells qualify as transformed T lymphocytes . The identification of scattered transformed T lymphocytes in an infiltrate does not, in turn, discriminate between benign and malignant T cell infiltrates. Transformed lymphocytes may be encountered in the infiltrates of reactive processes; when identified, they might be characterized as Lutzner cells. The cell at the tip of the green arrow is troubling; not only are the nuclear features those of a transformed T cell, but the size of the atypical nucleus is worrisome.