Objective: Regulatory Τ-cells (Τregs) participate in tumor tolerance and facilitate tumor growth and Foxp3 transcription factor is necessary and sufficient for their development and function. We investigated the presence of T-regs in invasive (IN) and in situ (IS) squamous cell carcinoma (SCC) of the skin and actinic keratosis (AK). Method: Tregs were identified using immunohistochemistry for Foxp3 and recorded using image analysis in 55 cases of INSCC (and their adjacent IS, AK or benign tissue (BN), when present), in 18 cases of IS and 46 cases of AK (and their adjacent BN tissue). Statistical analysis was performed using the paired T-test. p-values <0.05 were considered statistically significant. Results: In INSCC cases, Τregs in the tumor were more numerous than the adjacent ΒN (n=46) (mean 155 vs. 79, p <0,001). Additionally, adjacent IS had more Tregs than adjacent AK (n=6) (160 vs. 86, p=0,045). Significant differences between INSCC, and IS or AK were not observed. In IS and AK cases, Τregs were more numerous than the adjacent BN (206 vs. 42, p<0,001 and 148 vs. 47, p< 0,001), respectively. Conclusion: Treg infiltration of the skin increases early from the precancerous AK, indicating early involvement of Tregs in the development of SCC. Objective: Mastocytosis is a rare disorder and its true incidence is unknown. Skin is most commonly involved, followed by the bones and the gastrointestinal tract. Method: Five men presented with many brown lesions in the trunk and one woman with multiple redish brown nonpruritic macules in the extremities. We used immunohistochemistry for c-kit and tryptase for the definite diagnosis. The expression of CD25 and CD2 were also evaluated. Results: Histology showed five cases of urticaria pigmentosa with severe diffuse infiltration of the papillary dermis by mast cells and one case of telangiectasia macularis eruptiva perstans (TMEP) with scattered mast cells around dilated capillaries and venules of the papillary dermis. The mast cells were positive to c-kit and tryptase and only in one case there was a coexpression of CD25 and CD2 >50 % of the mast cells. In that case involvement of bone marrow was observed and the diagnosis of indolent systemic mastocytosis was established according to WHO 2008 criteria. Conclusion: Urticaria pigmentosa is the most common form seen in adults while TMEP is an uncommon form that occurs exclusively in adults. The skin involvement in indolent systemic mastocytosis is a part of the spectrum of the disease.