A Case of Malignancy-associated Histiocytoid Sweet Syndrome in a Patient with AML / 대한피부과학회지

Sweet syndrome is a disorder characterized by painful, erythematous, cutaneous plaques and nodules of rapid onset accompanied by fever, leukocytosis, and neutrophilia. We encountered a case of a recurrent histiocytoid Sweet syndrome in a patient with acute myeloid leukemia (AML). A 64-year-old Korean man was diagnosed with complete remission of AML and had symptomatic nodules and plaques on the dorsal sides of both hands. Approximately 3 years prior, he also had symptomatic plaques at the same site and had been diagnosed with MDS (Myelodysplastic syndrome). We performed a biopsy and diagnosed this case as a malignancy-associated histiocytoid Sweet syndrome. Most Sweet syndrome cases are acute; in contrast, this case was chronic with a relapse. In addition, histopathologic examination showed a dense histiocytic infiltration. These histiocytoid cells are usually misinterpreted as histiocytes; however, they are actually immature myeloid cells. Herein, we report a case of a recurrent malignancy-associated histiocytoid Sweet syndrome in a patient with a hematologic disorder.

Histiocytoid Sweet Syndrome in a Child without Underlying Systemic Disease

Sweet syndrome (acute, febrile, neutrophilic dermatosis) is characterized by the acute onset of an eruption of painful nodules or erythematous or violaceous plaques on the limbs, face and neck. These symptoms are accompanied by fever. The diagnostic features include histopathological findings of dermal neutrophilic infiltration without leukocytoclastic vasculitis or peripheral blood leukocytosis. Sweet syndrome is associated with infection, malignancies, autoimmune disease, pregnancy, and drugs. Patients with Sweet syndrome demonstrate a complete and rapid response to systemic steroid administration. Recently, a distinct variant of Sweet syndrome was reported, termed “histiocytoid Sweet syndrome”, in which the infiltration of myeloperoxidase-positive histiocytoid mononuclear cells are observed (in contrast to the infiltration of neutrophils). The other clinical features are similar to those of classic Sweet syndrome. Pediatric Sweet syndrome is uncommon, and the histiocytoid type is even rarer. To date, four cases of histiocytoid Sweet syndrome have been reported in children. Herein, we describe a case of histiocytoid Sweet syndrome in an otherwise healthy 10-year-old boy with no underlying systemic disease in whom non-steroidal, anti-inflammatory drug treatment was successful.

A Case of Histiocytoid Sweet Syndrome without a Hematologic Disorder / 대한피부과학회지

Histiocytoid Sweet syndrome (HSS) is a recently described rare variant of acute febrile neutrophilic dermatosis. HSS is clinically characterized by painful inflammatory plaques or nodules with high fever and neutrophilia. About 20% of HSS patients also have an associated malignancy, most commonly of hematologic origin. Histopathologically, HSS is characterized by dense histiocytic infiltration with prominent upper dermal edema, and little neutrophil infiltration. A 69-year-old female presented with a 1-week history of painful erythematous plaques on both elbows accompanied by fever. She was diagnosed with acute pyelonephritis and treated with ciprofloxacin for 2 weeks. Routine laboratory tests showed elevated white blood cell count (predominantly neutrophils), erythrocyte sedimentation rate, C-Reactive Protein, and a mildly elevated liver function test. Peripheral blood smears were normal. Histopathologic examination showed papillary dermal edema and diffuse interstitial infiltration of histiocytoid cells. Immunohistochemical studies revealed that the histiocytoid cells were positive for CD 68 and myeloperoxidase. After treatment with systemic glucocorticoids, the skin lesions and fever gradually resolved. Based on the clinical and histopathologic examination, we diagnosed HSS with no evidence of a hematologic disorder. Herein, we report an unusual case of HSS without associated bone marrow dysplasia.

A Case of Histiocytoid Sweet Syndrome Developed in the Patient with Pure White Cell Aplasia / 대한피부과학회지

Histiocytoid Sweet syndrome (HSS) is a rare inflammatory disease that has recently been described as a variant of Sweet syndrome. Histopathologically, HSS is characterized by papillary dermal edema with infiltration of histiocytoid cells into the upper dermis. The histiocytoid cells are easily misinterpreted as histiocyte, but in fact, they are immature myeloid cells. To demonstrate cells of myeloid lineage, specific staining must be performed, such as myeloperoxidase (MPO). To date, there are several HSS cases associated with hematological malignancy, drugs, and chronic inflammatory diseases. But, in Korea, only one case has been reported so far. Herein, we report a case of HSS developed in the patient with pure white cell aplasia and review the relevant literature.

A Case of Histiocytoid Sweet's Syndrome with Myelodysplastic Syndrome / 대한피부과학회지

Sweet's syndrome is an acute febrile neutrophilic dermatosis that occurs with malignant disease, mainly myeloid hemopathies, in about 20% of cases. When associated with myelodysplasia, clinical and histologic features of Sweet's syndrome can be atypical; however its significance is still debated. We encountered a case of Sweet's syndrome associated with myelodysplastic syndrome in a 63-year-old woman. The clinical presentation strongly suggested Sweet's syndrome but, histopathologic examination showed dense histiocytic infiltration with prominent upper dermal edema and little neutrophil infiltration. In the evaluation for atypical histopathology and laboratory abnormalities, she was diagnosed with myleodysplastic syndrome by peripheral blood smear and bone marrow biopsy. Histiocytoid Sweet's syndrome is a currently accepted concept and probably has a close relation with underlying myeloid hemopathies.