Table 2 demonstrates the sex and anatomic location of the patients in the 35 reported cases of DFSP described as atrophic or morpheaform, including the present case. The majority (20/35) of cases have been in female patients, and the most common location in both sexes has been the trunk (24/35). The next most common location was the lower extremity (7/35).
Table 3 documents the age and anatomic location of the 9 cases clinically described as resembling lipoatrophy, atrophoderma or anetoderma, or that were significantly clinically depressed based on clinical photographs, ie, the cases most similar to the one we now present.4,16,19-21,25 Three of the 9 cases were on the trunks of females aged 16 to 41 years. Interestingly, 4 of the remaining 6 cases were on the lower extremities of children aged 18 months to 16 years.
A number of conclusions can be drawn from this data. First, atrophic variants of DFSP tend to occur most often on the trunk, as do the usual variants of DFSP. However, the atrophic variants tend to occur more often in females as opposed to the standard presentation of DFSP, which occurs with equal frequency in males and females. In addition, a distinction exists in the presentation of atrophic lesions, which can have either a morpheaform or a more clinically depressed appearance, mimicking such disorders as anetoderma, atrophoderma, or lipoatrophy. We report such a case mimicking atrophoderma, and we contend that this is the rarest presentation of atrophic DFSP.
One final entity in the differential diagnosis of a depressed plaque on the trunk would be an atrophic dermatofibroma. The dermatofibroma, a well-known and benign cousin of DFSP, is often noted to have some dermal atrophy grossly with lateral pressure, described as a dimple sign.27 As Requena and Reichel28 pointed out, even when there is a central depression over a dermatofibroma without lateral pressure, no true loss of the dermis is seen histopathologically. As such, this central depression doesn't represent true dermal atrophy.28 However, the dermatofibroma also can present as a depressed lesion demonstrating thinning of the dermis histologically, and this variety of dermatofibroma has been described as atrophic.28-31 Although a recently published article recommended considering a diagnosis of atrophic dermatofibroma in the case of "atrophic, depressed lesions on the upper body of middle-aged women,"31 we would maintain that atrophic DFSP also should be considered in the differential diagnosis.
One possibility to clarify the imprecision in the literature in relation to the clinical presentation of DFSP would be to eliminate protuberans from the name, thereby recognizing that some lesions that are histologically proven to be DFSP can present without nodularity and with epidermal or dermal atrophy. This change in the nomenclature was first proposed by Lambert et al23 and was reiterated by Page and Assaad.16 Perhaps a greater awareness that DFSP can present as atrophic lesions without nodules could lead to earlier diagnosis and decreased morbidity with smaller curative surgeries when the lesions are recognized at an earlier stage. The atrophic variant of DFSP does not carry a different prognosis compared with the traditional variant; Mohs micrographic surgery is still the treatment of choice, providing a low rate of recurrence. Atrophic DFSP should be kept in the differential diagnosis for atrophic, depressed lesions, particularly those seen on the trunks of women or on the lower extremities of children.