Pigmented and irritated types of seborrheic keratosis (SK) can be confused with melanoma, basal cell carcinoma, or pigmented actinic keratosis. Dermoscopic examination may give many clues for the diagnosis of SK, but in equivocal cases the accurate diagnosis can only be made by microscopic features. Herein, we report a striking, isolated pigmented and inflamed SK, located on the waist in an elderly man. Although the duration of the lesion was not clear, a recent change in color was reported. The striking dark pigmentation and lack of visible characteristic features for SK led us to consider other pigmented lesions, mainly melanoma, which it closely resembled. Dermoscopic examination was inconclusive with subtle clues for SK, such as brown-gray dots, small brownish clods, a few curved short lines, and few small pinkish round structures. Histopathological and immunohistochemical examinations revealed an inflamed and pigmented SK. In conclusion, pigmented and inflamed SK does not usually tend to show typical dermoscopic features of SK and may mimic other pigmented lesions, including melanoma. All skin lesions that cannot be classified as clearly benign should undergo biopsy.

Milia-like idiopathic calcinosis cutis (MICC) and subepidermal calcified nodule (SCN) are described as different entities under the heading of idiopathic calcinosis cutis. Although there are some clinical differences, they share many features. Whereas MICC lesions are located mostly on the extremities and rarely on the face, SCN manifests itself mostly on the face, rarely on the extremities. Milia-like idiopathic calcinosis cutis almost always presents with multiple lesions, whereas SCN shows mainly solitary and rarely multiple lesions. Association with Down syndrome (DS) has been reported in up to two-third of the cases with MICC, but not in SCN. We herein present a 5-months-old girl without DS, manifesting a 2mm solitary, white hard papule surrounded by erythema, located on the finger. Histopathologic findings revealed the presence of dermal calcium deposits. When a solitary papular lesion of idiopathic calcinosis is seen in a child, especially if not associated with DS, it is difficult to differentiate MICC from SCN. We believe that these entities may represent variants of the same pathology and it may be more appropriate to designate a solitary lesion as SCN, regardless of its location.