Objective: GSS is a very rare variant of MF. We describe an additional case of this rare disorder in a 42 yo female that has been approved by TCRB&G Tcell Clonality Assay. Method: A 42 yo female with a single bulky skin lesion in the inguinal fold which had first appeared 6 y before and enlarged up to 20 cm, referred to plastic surgery for esthetics. H&E section of the deep skin biopsy of lesion showed a granulomatous infiltrate in the dermis. Nuclear atypia and epidermotropism is not significant. But there is numerous multinucleated histiocytic giant cells. Elastophagocytosis are present. TCRB&GT cell Clonality Assay showed a clonal rearrangement in TCR gamma gene. She was referred to dermatology for treatment and now she is getting UVA1 phototherapy. Results: The diagnosis of GSS is difficult in early stages of the disease. Clonal rearrangement of TCR genes can be a useful diagnostic tool in early stages of the disease. Conclusion: 20-50 % of patients with GSS carry a risk for the development of a second malignancy. GSS may be associated with lymphoproliferative disorders. Therefore, follow up of the patient is important. This case report supports that GSS is an indolent variant of MF due to clinical, histological and T-cell gene rearrangement results.