Histiocytoid Sweet's Syndrome in the Setting of Myelodysplastic Syndrome

Abstract

Acute febrile neutrophilic dermatosis, or Sweet's syndrome, is characterized by tender, edematous papules and plaques, favoring the upper extremities and the head and neck regions. The classic variant of Sweet's syndrome involves a predominantly neutrophilic dermal infiltrate on histopathology. However, histiocytoid Sweet's syndrome has been noted to have a primary histiocytoid mononuclear infiltrate and is typically found in patients with malignancies such as myelodysplasia. This case report discusses the treatment of histiocytoid Sweet's syndrome in an immunocompromised patient with a recent history of Mycobacterium avium complex infection and latent tuberculosis in the setting of myelodysplastic syndrome.

Keywords: clinical dermatology; histiocytoid; malignancy-associated sweet syndrome; myelodysplasia; sweet's syndrome.

Figure 1. Juicy, edematous papules and plaques scattered near the mandible and anterolateral neck

Figure 2. Erythematous, edematous plaques and nodules on the left hand and the left dorsal forearm

Figure 3. Erythematous papules and plaques on the left upper arm

Figure 4. Significant interstitial and perivascular histiocytoid and lymphoid infiltrates seen in the dermis with edema present (hematoxylin and eosin stain 40x)

Figure 5. Scattered histiocytoid and lymphoid cells seen with prominent nucleoli and nuclear atypia; notably, there is a paucity of mature neutrophils in the inflammatory population (hematoxylin and eosin stain 400x)