A previously healthy 23-year-old woman was observed with erythematous and infiltrated plaques associated with significant skin flaccidity forming a pendulous skin fold in the right armpit and a brown macular pigmentation with mild skin flaccidity in the left armpit (Fig. 1). Lesions were asymptomatic and had a 2-year evolution.

Figure 1 A: skin lesions in both armpits with a 2-year evolution. B: erythematous and infiltrated plaques associated with significant skin flaccidity in the right armpit. C: brown macular pigmentation with mild skin flaccidity in the left armpit. 

A skin biopsy of the right armpit revealed a dense dermal granulomatous infiltrate of atypical lymphocytes, neutrophils, histiocytes, plasma cells, eosinophils, and scarce multinucleated giant cells (Figs. 2A-C). Verhoeff staining demonstrated a marked reduction of elastic fibers (Fig. 2D). Immunohistochemistry of the dermal infiltrate showed positivity for cluster of differentiation (CD) 3 and 4 (Fig. 3) and loss of CD7 and CD8 expression, findings that are compatible with the diagnosis of granulomatous slack skin (GSS).

Figure 2 Hematoxylin-eosin-stained sections at ×40, ×200 and ×400, respectively. A: dense granulomatous infiltrate affecting the entire dermis and subcutaneous tissue. B: atypical lymphocytes, neutrophils, histiocytes, plasma cells, eosinophils composing the granuloma. C: scarce multinucleated giant cells. D: verhoeff-stained section at ×600; reduction of elastic fibers. 

Figure 3 Immunohistochemistry showing atypical cells expressing: A: CD3+; B: CD4+. 

GSS is a rare variant of mycosis fungoides that mainly affect caucasian men between the third and fifth decades of life¹,².

Histology shows, in addition to elastophagocytosis and emperipolesis, a granulomatous infiltrate mainly composed by atypical lymphocytes, macrophages, and multinucleated giant cells with 20-30 nuclei¹-³. This last aspect was not found in our patient and to the best of our knowledge, only another similar case has been reported⁴. Regarding immunohistochemistry, it demonstrates a cell with a T-helper immunophenotype¹, as in the present case, with monoclonal rearrangement of T-cell receptor genes in most tested patients¹,². In addition, some subpopulations of macrophages secrete metalloproteinases that are considered responsible for the degradation and remodeling of the dermal tissue³.

Furthermore, other lymphoproliferative disorders may be present in up to 50% of cases, so patients must be screened and followed up¹,². Due to its rarity, there is no standard treatment, and a complete remission of the disease has seldom been reported⁴-⁶.