Multiple Tumors of the Follicular Infundibulum: A Cutaneous Reaction Pattern?

A remarkable feature in our case was the patient’s severe pruritus, as most reported cases have been asymptomatic. The increased association with other cutaneous lesions,² the Köbner phenomenon, and the underlying inflammatory cell infiltration of the tumors in our case strongly suggested that eruptive TFI may represent a kind of cutaneous reaction.

Figure 3. Histopathologically, a benign platelike proliferation of pale-staining keratinocytes and follicular structures could be observed in the papillary dermis connected to the overlying epidermis with a moderate lymphatic cell infiltration (A)(H&E, original magnification ×40). Weigert staining showed a network of black-blue elastic fi-bers at the base of the tumor (B) (original magnification ×200). The pale kerat- inocytes were positive on periodic acid–Schiff staining (C)(original magnification ×100). Immunohis-tochemically, the proliferation of keratinocytes was positive for keratin 17 (D)(diaminobenzidine, original magnification ×100).

Conclusion

The clinical findings of severe pruritus and the Köbner phenomenon in our patient further expand the constellation of the clinical presentation of the eruptive variant of TFI.