Dilated pore of Winer in a dog

A 9-year-old male neutered Goldendoodle was presented to the Animal Medical Center of Seattle with a history of a firm, hairless, cystic mass on the dorsal aspect of the neck. The mass had been present for 2 years and would periodically rupture and discharge moderate quantities of yellow-green, soft, semi-solid, keratinaceous material. As rupture of the mass was reported to cause the patient significant pain and discomfort, it was surgically excised. Histopathology of the mass revealed a bulbous keratin-filled cyst that communicated with the external environment via a small ostium. At the base of the cyst, the cyst lining was characterized by a markedly irregular and hyperplastic stratified squamous epithelium with an overt stratum granulosum and prominent, irregularly sized, shaped and spaced rete ridges. At the superficial aspect of the cyst near the ostium, the cystic lining was characterized by a relatively thinner stratified squamous epithelium with an overt stratum granulosum and regular basal contour. Based on the histomorphological appearance of the mass, a diagnosis of a dilated pore of Winer was made. Dilated pores of Winer are follicular cysts arising from the infundibulum of the hair follicle. They are relatively common in humans and uncommon in cats, and single case reports have been described in a horse and a woodchuck (Marmota monax). To the best of the authors' knowledge, this is the first description of a dilated pore of Winer in a dog.

Two cases of infundibular squamous cell carcinoma on the nose with aggressive clinical behavior: Case report and review of the published work

Case 1 was a 75-year-old Japanese man who presented with a poorly demarcated, dark-red nodule with a destructive defect in the center, measuring 3 cm × 2 cm on the right wing of his nose. The histological diagnosis was a common form of infundibular squamous cell carcinoma. Atypical neoplastic cells radiated from the wall of a follicular infundibulum. The majority of neoplastic cells were positive for AE1/AE3 and 34βE12. Cytokeratin 17 expression was seen in the suprabasal cells of the deeply situated neoplastic components. Case 2 was a 73-year-old Japanese man who presented with a poorly demarcated, dark-red nodule with an irregularly shaped ulcer in the center, measuring 3 cm × 2 cm on the left wing of his nose. The histological diagnosis was a crater form of infundibular squamous cell carcinoma. Atypical neoplastic cells radiated from the broad base of the central keratin-filled crater, continuous with two infundibular canals. In both cases, some of the more deeply situated aggregations were composed of neoplastic keratinocytes with eosinophilic glassy or pale cytoplasm. In addition, no atypical keratinocytes could be seen in the interfollicular epidermis. In case 1, a hematogenous metastasis to the vocal cord and the forehead occurred in addition to a lymph node metastasis. In case 2, a local recurrence occurred with an intralymphatic dissemination. We describe two cases of infundibular squamous cell carcinoma on the nose with aggressive clinical behavior, one of which was accompanied by a hematogenous metastasis while another revealed a local recurrence.