A dermal infiltrate of leukemic cells results in the papulonodular lesions, or plaques, that are illustrated here. Such primary involvement of the skin is relatively rare in childhood leukemia. The wide variety of secondary manifestations of leukemia includes petechiae and ecchymoses and pyoderma gangrenosum. A polymorphonuclear dermal infiltrate termed Sweet's syndrome (see Fig. 13-18) may be associated with leukemia. In addition, children receiving chemotherapy are prone to bacterial and fungal infections of the skin, severe varicella, and ulcerative or chronic herpes simplex.
Like other lymphoproliferative disorders, Hodgkin's disease may have both specific and nonspecific cutaneous manifestations. Figure 21-3 illustrates a relatively rare event in children with Hodgkin's disease: the direct infiltration of malignant cells into the skin. A biopsy analysis of these brownish papules, nodules, and plaques reveals a histology similar to that of affected lymph nodes. These lesions may occasionally ulcerate, and pruritus is a distressing symptom.
Also known as granulocytic sarcomas, these lesions may be seen in acute and chronic myelocytic leukemias. The lesions, which are infiltrates of masses of leukemic cells, occasionally present with a green color due to myeloperoxidase activity.
This malignant tumor of the autonomic nervous system occurs most frequently in young children. Metastatic disease is often present at the time of diagnosis. Cutaneous metastases appear as bluish papules or nodules involving the trunk or extremities.
The lesions are sometimes noted to blanch upon stroking and may sometimes exhibit increased sweating. Children who are under 1 year of age at the time of diagnosis, as was the case in the patient in this figure, may experience spontaneous regression of their illness. The prognosis in older children and in those with very widespread disease tends to be poor.
This is a spectrum of disease that encompasses Letterer-Siwe disease, Hand-Schüller-Christian disease, and eosinophilic granuloma. The disorder is characterized by the proliferation of Langerhans' histiocytes in the skin and other organ systems. Figure 21-7 shows the characteristic seborrheic-like, scaly, erythematous eruption on the scalp, face, and ears. Figure 21-8 shows a more popular presentation in a similar location. The presence of petechiae is a particularly helpful sign. Diagnosis is confirmed by skin biopsy and electron microscopy. More rapid confirmation is sometimes possible if one observes the presence of histiocytes in a lesion that has been scraped onto a microscopic slide and stained. Langerhans' cell histiocytosis may be accompanied by ...