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LYMPHOCYTIC INFILTRATES OF THE DERMIS (tier 2)
The lymphocytic infiltrates of the dermis are basically perivenular infiltrates; using A.B. Ackerman’s criteria, they would be both “superficial and deep”
perivascular infiltrates; nodular or tumoral components, as seen in the cutaneous lymphoplasias, are not a feature (temporality may be an influence in the expression of histologic patterns; some lesions, initially
showing perivenular patterns, may, at a later date, be manifested in tumoral patterns of a benign lymphoplasia). Typically, the perivenular components of a lymphocytic infiltrate are composed mostly of lymphocytes (S5C24P17-1, & S5C28P21-1 & 2).
In classic examples, the infiltrates are sufficiently dense to be characterized as “cuffs of lymphoid cells.” The category includes variants such as: erythema annulare centrifigum, polymorphic light eruption, and
lymphocytic infiltrate of Jessner (whatever lymphocytic of Jessner may represent). Drug eruption should be considered in the differential diagnosis. Some lesions of lupus erythematosus may present the patterns of a
lymphocytic infiltrate and may lack evidence of a significant epidermal involvement. The infiltrates of chronic lymphocytic leukemia in the skin may present the pattern of a lymphocytic infiltrate.
The epidemis over a lymphocytic infiltrate of the dermis usually is not significantly altered. In some examples, the epidermis will show spotty areas of mild
liquefaction degeneration at the D-E interface (S5C24P17-2-6). If even mild epidermal changes of a
cell-poor lichenoid type are identified, LE should be mentioned in the differential diagnosis. A relationship between LE and polymorphic light eruption has, on occasion, been proposed but has not been clearly
defined. If, in a single lesion, lichenoid patterns at the dermal-epidermal interface are combined with significant dermal mucinosis, and if the setting is basically a lymphocytic infiltrate of the dermis, the need
to rule out LE is great.
An interstitial component is fairly common in the category of the lymphocytic infiltrates (S5C24P17-4 & 5). Often the interstitial component is inconspicuous, but in some examples, extensions
of the lymphoid infiltrates into the reticular dermis among collagen bundles is a prominent feature. If a lymphocytic infiltrate of the dermis has a prominent interstitial component, it is likely that the dermis in
the area of the interstitial infiltrates will also show some degree of mucinosis (S5C24P17-3, S5C27P20-3-6, & S5C29P22-1). It is not
possible to make a distinction between a lymphocytic infiltrate of LE and some other type of lymphocytic infiltrate by attempts to quantitate the degree of mucinosis.
Two variants of erythema annulare centrifugum (EAC) have been described. The deep variant shows the classic pattern of a lymphocytic infiltrate of the dermis (S5C26P19-1-3). The superficial variant shows the pattern of a reaction involving the superficial reactive unit of the skin (the epidermis and
the papillary dermis) (S5C26P19-4-6, & S5C27P20-1-2).
In the superficial variants, the infiltrates are more limited in distribution; focally, lymphocytes and histiocytes will be found in the epidermis in areas of spongiosis. There often are spongiotic vesicles. The
variations in patterns may, in large part, be a reflection of the area selected for biopsy. Tthe patterns near the margin of the lesion may be different from those in a more central location. Eosinophils may be
found in the infiltrates of EAC.
Polymorphic light eruption may show mild, spotty areas of vacuolar degeneration at the D-E interface. Papillary dermal edema has been emphasized as a feature of the
lymphocytic infiltrate of polymorphic light eruption but, in my experience, is not often a prominent feature.
“Lymphocytic infiltrate of Jessner” often shows prominent perivascular cuffs of lymphoid cells in the reticular dermis. In the selected example, focal collections of
transformed lymphocytes are a feature. The selected example was a lesion showing the pattern of a lymphocytic infiltrate S5C25P18-1-5. A subsequent biopsy of a subcutaneous tumor from this same patient showed a large B cell
lymphoma.
Cerio R, et al: The heterogeneity of Jessner’s lymphocytic infiltration of the skin. J Am Acad Dermatol 1990;23: 63-7.
MISCELLANEOUS LICHENOIDS
Macular amyloidosis
is a spotty, cell-poor lichenoid reaction. In the areas containing amyloid deposits, the basal layer of the epidermis often is interrupted. In early lesions, the deposits may be found in lytic defects at the dermal-epidermal junction (S5C28P21-3). In more advanced lesions, the deposits will be prominent in the papillary dermis, usually in the tips of dermal
papillae. They may also be found in defects in the basal unit of the epidermis and in the cytoplasm of individual keratinocytes in the overlying epidermis (S5C28P21-4-6).
Rosacea is manifested, early on, in patterns of perifolliculitis, telangiectasia, and mid-dermal atrophy (S5C28P21-7). In some lesions, spotty areas of vacuolar degeneration at the dermal-epidermal interface may be a feature (on
the basis of this variable feature, a brief presentation of the pathology of the angiectatic variant of rosacea is included in this section).
The epidermis of a lesion of Degos disease
shows atrophy, effacement of rete ridges, and liquefaction degeneration at the D-E interface; the patterns have a lichenoid quality, with LE-like features (S5C29P22-2, & S5C29P22-4). In
addition, dermal mucinosis may be a prominent feature (S5C29P22-3 & 4). Perivenular infiltrates of lymphoid cells in the
reticular dermis are a feature. In well-developed lesions, an arteriole in the dermis often will show fibrous obliteration of its lumen (S5C29P22-5 & 6); the accompanying vein often shows interstitial lymphoid infiltrates.
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