A 47-year-old male patient noticed a change in his voice (hoarseness) 4 months previously. During the anamnesis, he did not report any addictions or habits, but systemic hypertension had been diagnosed and controlled. During intraoral physical examination, a pediculated exophytic lesion with a rough surface and coloration similar to adjacent mucosa was observed in the right tonsil. Examination by laryngoscopy revealed an exophytic lesion in the right paralyzed vocal fold, occupying its anterior two-thirds, in which the mucosa was covered by fibrinopurulent exudate. An incisional biopsy was performed on the vocal cord and excisional on the palatine tonsil. Microscopically, the vocal cord biopsy revealed a squamous epithelium exhibiting architectural disorganization, covered by a fibrinopurulent membrane. This epithelium exhibited projections towards the connective tissue and was infiltrated into the connective tissue, forming islands and strands of malignant epithelial cells (Figure 1).
The squamous layer showed clear epithelial cells with a vacuolized nuclei, and some cells similar to koilocytes were present in the upper layers of the epithelium. The epithelium was found with digitiform projections and fibrovascular connective tissue centers containing mononuclear inflammatory infiltrate (Figure 1(a)). A transitional zone was found in this biopsy, where the atypical epithelium protrudes exophytically with a digitiform aspect (Figure 1(b)). The malignant component showed atypical cells, with nuclear pleomorphism, sometimes binucleated cells, with a hyperchromatic nucleus and individual keratinization. Atypical mitoses and areas of necrosis were also found (Figure 1(c)). The result of the incisional biopsy was of a well-differentiated squamous cell carcinoma (SCC) present in the right vocal cord. Histological examination suggested that the SCC originated from a papillomatous lesion, and chromogenic in situ hybridization (CISH) was performed. Both lesions showed a positive result in CISH for high-risk HPV types 16 and 18 (Figures 1(d) and 1(e)) and negative for low-risk HPV types 6 and 11.
On the other hand, the histological sections of the right palatine tonsil region revealed a squamous papilloma demonstrated by proliferation of the stratified squamous epithelium, predominantly nonkeratinized, presenting exocytosis and basal layer hyperplasia with typical mitoses.
The following procedures were carried out from the biopsy block: dewaxing, peroxidase blockade, and enzymatic digestion, followed by a pretreatment with a 95% EDTA bath for 15 min, followed by several rinses with distilled water and dehydration. After drying, the probe was added onto the material, the slices were covered by a coverslip, and sealing was performed. The material was denatured for 5 min at 75 C, and hybridization was performed at 37 C for 60 min for high-risk HPV. The ZytoFast Plus CISH Implementation Kit-HRP-DAB (ZytoVision, Bremerhaven, Germany, and the ZytoFast HPV-type 6/11 Probe and 16/18 Probe) was used. In the next step, the coverslip was removed, and the slides were washed in TBS buffer at 55 C for 5 min, and then, the primary antibody was incubated at 37 C for 30 min in a humid chamber. For tagging, chromogen diaminobenzidine (DakoCytomation, Carpinteria, CA, USA) was used for 10 min, and Mayer's Hematoxylin was used for the counterstaining. Reactions were performed with negative and positive controls.
Surgery was performed, including tracheostomy, with the final diagnosis of SCC originating from LP, staging T3N0M0. One month after the surgical procedure, the patient returned without complaints. In the other nasofibroscopy and bronchoscopy examinations, no changes were observed. Follow-up by a speech therapist was fundamental for significant voice improvement. The patient has been undergoing maintenance for 36 months and has no complaints and no signs of relapse.
Fifteen articles were found, totaling 27 cases of malignant transformation of LP with onset in adult patients. The mean age of the patients was 57.03 years (SD = 13.76). Of these, including the present case, 25 (89.28%) were male patients (Table 1), and in 3 (10.71%) cases, there was no history of recurrent LP. The localization of the carcinoma was cited in 10 cases, of which 3 (30%) were malignant lesions in the lung, due to dissemination. In the remaining 7 (70%), the larynx was affected, mainly in the vocal cords. There were 9 (47.36%) smokers, and HPV was identified in 9 of the reports, 2 negative tests, 4 with low-risk HPV and 4 with high-risk HPV.