History
Patients with B-cell pattern pseudolymphoma present with a nodule or a group of discrete nodules, usually with minimal associated symptoms. Occasionally, patients present with pruritus or pain. Patients with a T-cell pattern of cutaneous pseudolymphoma usually present with broader patches, which are often asymptomatic.
The onset of drug-induced pseudolymphoma is insidious. Most patients present with a single slowly enlarging papular, nodular, or plaquelike lesion several weeks following the initiation of implicated medications. However, several patients have demonstrated drug-induced pseudolymphoma after more than 5 years of therapy.
Physical Examination
Examination of patients with a B-cell pattern of pseudolymphoma usually reveals a single nodule, from one to several centimeters in diameter. Although the lesions may be soft, they are more often firm. Typically, the lesions are red to purple in color, but they may show no coloration. Approximately three quarters of cases of cutaneous pseudolymphoma are localized. The remaining cases usually show grouped papules in a single defined region. More disseminated cases are rare. The most common site of involvement in cutaneous pseudolymphoma is the face (70%), followed by the chest and the upper extremities. Cutaneous pseudolymphoma lesions are infrequent below the waist.
Sites of predilection for borrelial pseudolymphoma include the earlobe, the nipple, the areola, the nose, and the scrotum (sites of low skin temperature). [9]
Patients with T-cell pattern pseudolymphoma typically present with broad, erythematous patches and/or plaques. Pseudolymphomatous actinic reticuloid affects sun-exposed areas. Lymphomatoid contact dermatitis demonstrates lesions in areas where the inciting agent has come in contact with the skin. [25]
Erythematous patches, similar to mycosis fungoides (MF), may be seen, but, in contrast to MF, they may be more localized and not restricted to sun-protected sites. [4] Frequently, a small number of erythematous indurated papules, plaques, or nodules are seen. Rarely, a solitary tumor may appear.
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This localized example of pseudolymphoma shows an ill-defined, thin, erythematous plaque.
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Pseudolymphomatous drug eruption due to captopril, marked by erythematous to purple papules, patches, and plaques.
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This erythrodermic pseudolymphoma (T-cell pattern) typifies drug-induced pseudolymphoma, which is most often secondary to anticonvulsant therapy.
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Biopsy specimens of pseudolymphoma vary substantially, but they most often exhibit a mixed inflammatory infiltrate with prominent lymphoid follicle formation.
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This example of lymphocytoma cutis shows a localized, erythematous-to-brown, ill-defined plaque.
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Lymphocytoma cutis of the shoulder, composed of flesh-colored or erythematous nodules in small groups.
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This photograph of lymphocytoma cutis caused by an arthropod bite shows an erythematous scaling patch of the scalp with localized secondary alopecia.
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A mixed inflammatory infiltrate with germinal centers is indicative of lymphocytoma cutis.
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Well-developed lymphoid follicles in a background of mixed inflammatory cells with small lymphocytes are typical of lymphocytoma cutis.
