Is Tumor of Follicular Infundibulum a Reaction to Dermal Scarring?

Abstract

Tumor of follicular infundibulum (TFI) is currently believed to be a benign epithelial neoplasm with follicular differentiation. It has been suggested that TFI is associated with dermal scarring, but further investigation is needed to confirm this correlation. To approach this question, a retrospective study was presented, a total of 67 cases (64 lesions) were found in a search covering cases over a 10-year period. Overall, the presence of histological dermal scarring was noted in 34 of 64 (53.13%) cases. Of the cases where TFI was an incidental finding, the presence of dermal scarring was noted in 13 of 18 (72.22%) cases. Meanwhile, of the cases where TFI was the main diagnosis, the presence of dermal scarring was noted in 12 of 34 (35.29%) cases. This suggests that TFI may, in some cases, represent an epidermal reaction pattern to dermal scarring.

Tumor of follicular infundibulum–associated neoplasms

“…They found 23 of 64 lesions were associated with other neoplasms, including BCC (12.5%), actinic keratosis (7.8%), epidermal cyst (3.13%), squamous cell carcinoma (3.13%), lentigo maligna (3.13%), intradermal nevus (3.13%), and syringoma (1.56%). 3 Compared with the highest rate of associated lesions in the studied performed by Abbas and Mahalingam, 2 this study presented an association up to 35%. 3 They also attributed these associations to a reactive process.…”

“…Similarly, in 2015, Baquerizo et al 3 performed a retrospective study, reviewing 67 cases spanning ten years. They found 23 of 64 lesions were associated with other neoplasms, including BCC (12.5%), actinic keratosis (7.8%), epidermal cyst (3.13%), squamous cell carcinoma (3.13%), lentigo maligna (3.13%), intradermal nevus (3.13%), and syringoma (1.56%).…”

“… 2 Clinical variants include multiple or eruptive forms. 3 Histopathologically, solitary lesions present as platelike subepidermal proliferations of eosinophilic, pale-staining keratinocytes, creating a reticulated pattern. 3 , 4 …”

“…Basal cell carcinoma (BCC) is the most commonly reported association, with varying rates of associated lesions seen in other reports. 3 Here, we present the case of a 69-year-old man with TFI and an associated dysplastic nevus.…”

Tumor of the follicular infundibulum: Dermoscopic and confocal features

“…Based on this finding, some authors have recently questioned the classification of TFI as a benign tumor suggesting it may instead consist in a reactive process. [4][5][6] However, in 2013…”