No abstract

Diagnosis of basaloid squamous carcinoma (BSCC) currently relies mainly on histological criteria, with variable immunohistochemical results reported in small series. We explored the use of a battery of immunohistochemical stains to elucidate this diagnosis on 45 cases of BSCC. To further elucidate the immunohistochemical profile of BSCC, to explore potential genetic pathways of malignant transformation using proliferation markers, and to investigate a possible link with Human Papillomavirus (HPV). Forty-five cases of BSCC and 34 site-matched cases of squamous cell carcinoma (SCC) were obtained from the archives of the pathology department at our institution. Extensive literature review was undertaken utilizing Medline. Ber-EP4 is a useful diagnostic marker for BSCC, positive in 82% (37/45) of the cases and in 68% (23/34) of SCC. An alternative is the combination of cytokeratins CK14 and CK7, known to be negative, and CK1, known to be positive, which achieves an accuracy of 73% (33/45) in BSCC and 88% (30/34) in SCC. The two diagnostic approaches were in agreement in 66% of the cases; both methods were equally accurate in the divergent cases. Increased expression of the proliferation markers supports the concept that BSCC is a rapidly growing tumor. Results of p16 stains support an etiological link between BSCC and HPV; interestingly, HPV was present significantly more in BSCC (71% (32/45)), than in SCC (59% (20/34)) in this study (P=0.02).

Objectives. Pyriform sinus fistulae arise from disturbances in the development of the fetal third and fourth branchial pouches and are predominantly found on the left side. We report the rare case of a right-sided pyriform sinus fistula presenting as a lateral neck abscess. Study Design. Case report. Methods. A 24-year-old woman presented with a two-week history of right-sided neck abscess. A fluoroscopic sinogram revealed a fistulous tract extending from the abscess to the apex of the right pyriform sinus. It was determined that the fistula was likely a third or fourth branchial remnant, a rare right-sided finding. Chemocauterization of the fistulous tract with 40% trichloroacetic acid was used to successfully treat the patient. Results. Approximately 93–97% of branchial pouch anomalies are left sided. Treatment options include surgical excision and cauterization. Conclusions. Branchial cleft cyst and pyriform sinus fistula must be considered in the diagnosis of cervical abscess in either side of the neck.

Objectives. Pyriform sinus fistulae arise from disturbances in the development of the fetal third and fourth branchial pouches and are predominantly found on the left side. We report the rare case of a right-sided pyriform sinus fistula presenting as a lateral neck abscess. Study Design. Case report. Methods. A 24-year-old woman presented with a two-week history of right-sided neck abscess. A fluoroscopic sinogram revealed a fistulous tract extending from the abscess to the apex of the right pyriform sinus. It was determined that the fistula was likely a third or fourth branchial remnant, a rare right-sided finding. Chemocauterization of the fistulous tract with 40% trichloroacetic acid was used to successfully treat the patient. Results. Approximately 93-97% of branchial pouch anomalies are left sided. Treatment options include surgical excision and cauterization. Conclusions. Branchial cleft cyst and pyriform sinus fistula must be considered in the diagnosis of cervical abscess in either side of the neck.