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SECONDARY LUES (tier 2)
(a reaction pattern in the general category of lichenoid lymphocytic vasculitis)
The general category of the lichenoid disorders includes examples with prominent perivenular extensions of inflammatory infiltrates along vessels of the reticular dermis. Lesions, in which this combination of
features are prominent, might be grouped together as examples of lichenoid lymphocytic vasculitides. In this approach, a heterogeneous group can be accommodated; the distinctions, allowing for a subclassification of
these lesions, are subtle; they are not always developed to a degree which would impart exclusitivity. It is not always possible to identify morphologic features which might single out a particular subgroup. Some of
the lesions in this general group combine psoriasiform and lichenoid features; herein, some of the combinations equate with a characterization of the respective lesions as having pityriasic qualities. Some of the
lesions in this category are distinguished by a tendency for degenerating cells to cluster and for the clusters to be delivered to the surface of the skin. “Dropping-off” of necrotic cells into the dermis as seen in
the lichen planus-like disorders generally is not a prominent feature; the kinetics of the toilet of the epidermis in lesions of this category are different from those of a classic lesion of “lichen planus.” Lesions
showing this combination of “pityriasic” features might be characterized as erythema multiforme-like, or pityriasis lichenoides-like.
Lesions of secondary lues often show features that, by the above definition, would qualify as those of the general category, lichenoid lymphocytic vasculitis. In addition, the patterns are often pityriasic, combining
the features of a psoriasiform reaction with those of a lichenoid reaction. In the pityriasic-lichenoid subgroup, lesions of lues are additionally distinguishing by the presence of plasma cells in the infiltrates.
The infiltrates are also rich in migratory histiocytes, particularly in, and near, the epidermis, but the latter component, in itself, would not rule out either pityriasis lichenoides et varioliformis acuta or
erythema multiforme.
Lues generally is divided into three stages, the first stage being characterized as primary lues; it is manifested morphologically as a chancre. The chancre is an indurated lesion, that on palpation, has bulk. The
histologic patterns in a lesion of secondary lues generally include an epidermal component, an interface component, and perivenular components. For most examples, the combination of features might be characterized
as a lichenoid lymphocytic vasculitis with plasmacytosis. In many examples, morphologic features include psoriasiform patterns (hyperplasia of the basal unit with elongation of rete ridges) and lichenoid patterns
(infiltration of basal unit by lymphocytes, a high component of migratory histiocytes, and variable lytic defects at the dermal-epidermal interface).
For some examples, the psoriasiform patterns and the epidermal infiltrates provide a combination that additionally can be characterized as pityriasic (S4C10VA2-1-4); histologically, particularly at low magnifications, a lesion of secondary lues might be confused with a variant of
pityriasis lichenoides. Extravasation of rbc’s may even be a feature (S4C7P1-1-4).
For some example, the lytic phenomena, affecting the epidermis, are prominent; the patterns then take on a lichen planus-like quality (S4C7P1-5-6).
For some examples, the epidermis may be relatively atrophic with a straight interface, and with vacuolar changes at the dermal-epidermal interface (S4C8P2-1);
a lesion showing such a pattern might be characterized as a senescent lichenoid reaction.
With all the variations in epidermal patterns, attempts to define the histologic features of lesions of secondary lues often are challenging. In part, the variations in epidermal patterns may be evidence that each
lesion has a life history, and that the patterns are, in part, a measure of the stage of the evolution of a lesion at the time of biopsy.
The infiltrates of secondary lues often are band-like, and fill the papillary dermis (S4C8P2-1-2). They are pleomorphic with admixtures of
lymphocytes, migratory and activated histiocytes, and plasma cells. The representation of plasma cells in the band-like infiltrates is variable. The infiltrates also tend to be band-like in the adventitia of
follicles (S4C8P2-3). They may hug the follicles, and erode the basal layer (lichen planus-like phenomena). Although immunologists characterize
lues as a B-cell disorder - a process mediated at the level of antigen-antibody complexes - the histologic features are indicative of an important role for cellular immunity.
Infiltrates of inflammatory cells in lesions of secondary lues follow vessels into the deeper portions of the reticular dermis; often the infiltrates are dense and cuff-like (S4C8P2-4). The perivascular infiltrates are pleomorphic with a high component of histiocytes, and with a variable number of plasma cells. In some
examples, a significant number of plasma cells can be found in the perivascular infiltrates, even though plasma cells are difficult to find in the infiltrates of the papillary dermis. Vessels in the deeper portion
of the dermis often have thickened walls and swollen endothelium. Muscular vessels may show infitrates of inflammatory cells in their walls.
In some examples of secondary lues, the infiltrates, focally, may be granulomatous (S4C9P3-1). Granulomas generally are associated with tertiary
lues (S4C9P3-2).
In condyloma latum, the epidermal patterns are an exaggeration of the psoriasiform patterns seen in the cutaneous lesions of secondary lues; the epidermal changes often include lytic epidermal defects in which
neutrophils collect (spongioform pustular pattern) (S4C9P3-3-5). Spongioform pustular patterns occasionally are a feature of cutaneous lesions of
secondary lues (S4C9P3-6).
Secondary lues generally presents in a histologic pattern that has pityriasic qualities (S4C10VA2-1). In collecting virtual
images of the pityriasic disorders, hyperplasia of the basal unit of the epidermis is a common feature; the elongation of rete ridges that distinguishes the psoriasiform processes usually is not a striking feature (S4C10VA2-1-4). The spongiotic variants of pityriasic disorders essentially are characterized by the patterns of spongiotic
dermatitis (S4C10VA2-3). In the lichenoid category of pityriasic disorders, the basal unit is diffusely infiltrated by
lymphocytes and histiocytes, often without significant lytic defects (S4C10VA2-4); the patterns are subject to modifications,
depending on the age of the lesion selected for examination. In some examples, the patterns take on a lichen planus-like quality with the option for senescent lichenoid patterns. All of these variations also can be
encountered in lesions of secondary lues.
Gregory N, Sanchez M, Buchness MR: The spectrum of syphilis in patients with human immunodeficiency virus infection. J Am Acad Dermatol 1990;22: 1061-7.
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