Sweet Syndrome-like Dermatosis as a Precursor to Overlapping Hematologic Malignancies: A Case Report and Review

Abstract

Sweet syndrome (SS) is a rare neutrophilic dermatosis often associated with hematologic malignancies, particularly myelodysplastic syndromes (MDSs). We report a case of SS-like dermatosis in a patient with MDS who subsequently developed peripheral T-cell non-Hodgkin lymphoma (NHL). We review the literature on Sweet syndrome to contextualize this atypical presentation Methods: We present a case report of a 77-year-old male with leukopenia and known MDS, admitted for a persistent, infiltrated erythematous eruption. The patient underwent repeated dermatologic assessments, and serial skin and bone marrow biopsies with histopathologic and immunohistochemical analysis. A literature review was also conducted, focusing on SS in association with hematologic malignancies, including T-cell NHL. Results: Initial skin biopsies were inconclusive, and SS was diagnosed clinically based on lesion morphology and a prompt response to corticosteroids, despite the absence of definitive neutrophilic infiltrates. During follow-up, the patient's condition progressed with worsening cytopenias and recurrent febrile episodes. Repeat biopsies eventually confirmed the diagnosis of peripheral T-cell NHL with secondary hemophagocytic lymphohistiocytosis (HLH). Conclusions: This case illustrates the diagnostic uncertainty of SS-like eruptions in hematologic patients when histopathological findings are atypical or absent. Corticosteroid responsiveness may guide early diagnosis.

Keywords: Sweet syndrome; cutaneous manifestations; myelodysplastic syndrome; non-Hodgkin lymphoma.

Figure 1

Multiple violaceous, infiltrated papules and plaques, with erythematous bases and sharply demarcated borders.

Figure 2

Lesions on the trunk, upper limbs, and thighs, with a symmetrical distribution.

Figure 3

(Left): Skin biopsy showing a possible lymphoid infiltrate, diffusely distributed in the papillary and reticular dermis, without evidence of epidermotropism (Hematoxylin and Eosin (H&E), ×4 magnification). (Right): Atypical lymphoid infiltrate composed of medium- to large-sized discohesive lymphocytes with hyperchromatic nuclei, irregular nuclear membranes, and occasional visible nucleoli (H&E, ×40 magnification).

Figure 4

Cutaneous IHC showing diffuse membranous positivity for CD3 in dermal infiltrating lymphocytes (IHC, ×20 magnification), confirming peripheral T-cell lymphoma.

Figure 5

Bone marrow IHC. (Left): CD68 stain showing dense infiltration by histiocytes with strong cytoplasmic positivity, consistent with monocytic proliferation (IHC, ×20 magnification). (Right): CD7 stain highlighting monocytic lineage cells, supporting the diagnosis of hemophagocytic syndrome and acute monocytic leukemia (IHC, ×20 magnification).

Figure 6

Clinical decision pathway in suspected SS with underlying hematologic disease. Arrows indicate chronological sequence of clinical events and interventions.