BACKGROUND AND PURPOSE: Head and neck squamous cell carcinoma associated with human papillomavirus infection represents a distinct tumor entity. We hypothesized that diffusion phenotypes based on the histogram analysis of ADC values reflect distinct degrees of tumor heterogeneity in human papillomavirus–positive and human papillomavirus–negative head and neck squamous cell carcinomas. MATERIALS AND METHODS: One hundred five consecutive patients (mean age, 64 years; range, 45–87 years) with primary oropharyngeal (n = 52) and oral cavity (n = 53) head and neck squamous cell carcinoma underwent MR imaging with anatomic and diffusion-weighted sequences (b = 0, b = 1000 s/mm², monoexponential ADC calculation). The collected tumor voxels from the contoured ROIs provided histograms from which position, dispersion, and form parameters were computed. Histogram data were correlated with histopathology, p16-immunohistochemistry, and polymerase chain reaction for human papillomavirus DNA. RESULTS: There were 21 human papillomavirus–positive and 84 human papillomavirus–negative head and neck squamous cell carcinomas. At histopathology, human papillomavirus–positive cancers were more often nonkeratinizing (13/21, 62%) than human papillomavirus–negative cancers (19/84, 23%; P = .001), and their mitotic index was higher (71% versus 49%; P = .005). ROI-based mean and median ADCs were significantly lower in human papillomavirus–positive (1014 ± 178 × 10⁻⁶ mm²/s and 970 ± 187 × 10⁻⁶ mm²/s, respectively) than in human papillomavirus–negative tumors (1184 ± 168 × 10⁻⁶ mm²/s and 1161 ± 175 × 10⁻⁶ mm²/s, respectively; P < .001), whereas excess kurtosis and skewness were significantly higher in human papillomavirus–positive (1.934 ± 1.386 and 0.923 ± 0.510, respectively) than in human papillomavirus–negative tumors (0.643 ± 0.982 and 0.399 ± 0.516, respectively; P < .001). Human papillomavirus–negative head and neck squamous cell carcinoma had symmetric normally distributed ADC histograms, which corresponded histologically to heterogeneous tumors with variable cellularity, high stromal component, keratin pearls, and necrosis. Human papillomavirus–positive head and neck squamous cell carcinomas had leptokurtic skewed right histograms, which corresponded to homogeneous tumors with back-to-back densely packed cells, scant stromal component, and scattered comedonecrosis. CONCLUSIONS: Diffusion phenotypes of human papillomavirus–positive and human papillomavirus–negative head and neck squamous cell carcinomas show significant differences, which reflect their distinct degree of tumor heterogeneity.

Rosai-Dorfman disease (RDD) is a rare histiocytosis which involves principally lymph nodes. Thyroid involvement in RDD is a very rare situation, and lung involvement is even rarer. We report the case of a 46-year-old woman presenting a painless mass in the right side of the neck and subacute dyspnoea. Computerised tomography (CT) scans of the neck and thorax showed a large thyroid mass causing tracheal stenosis and multiple cystic lesions in both lungs. Subtotal thyroidectomy with a tracheal segment resection and histological analysis confirmed the diagnosis of nodal and extranodal (thyroid, tracheal and probably lung) Rosai-Dorfman disease (RDD) with the presence of increased numbers of IgG4-bearing plasma cells. Clinical, functional and radiological follow up 4 years after surgery without medical treatment did not show any disease progression. This case report indicates a benign course of nodal RDD with thyroid and tracheal infiltration following surgical resection, association of typical histological signs of RDD (emperipolesis) with IgG4-related disease features, and that lung cysts might be a manifestation of RDD.

Background: Peritonsillar abscess (PTA) is relatively common but challenging to diagnose clinically. Several clinical signs may be used, with unknown performances. We evaluated and compared the diagnostic performance of individual and combined clinical signs (trismus, edema, pharynx immobility, uvula deviation, hot potato voice, and overall clinical impression) assessed by an otolaryngologist and of contrast-enhanced computed tomography (CT) to detect acute PTA. Methods: Prospective study in 133 consecutive adult patients (77 males, mean age = 33 years) with suspected clinical PTA and CT obtained in the emergency setting of a tertiary care hospital between November 2020 and October 2022. The standard of reference consisted of surgically proven pus within 24 h of CT or a favorable clinical evolution at 48 h without surgical intervention. Results: PTA was present in 117/133 (88%) patients, with no difference between mean age or sex distribution between the groups with and without PTA. None of the evaluated clinical signs were associated with PTA (OR = 1.26–5.43, p > 0.05), whereas the CT finding “abscess” was significantly associated with PTA (OR = 67.2, p < 0.0001). The sensitivity of individual clinical signs varied between 19.7% and 73.5%, and the sensitivity of CT was significantly higher for all clinical signs (95.7%, p < 0.0001) except for overall clinical impression (97.4%, p = 0.7266). The specificity of clinical signs varied between 12.5% and 93.8%, and the specificity of CT was significantly higher (75%, p < 0.05) for overall clinical impression and edema. All clinical signs together yielded an area under the curve (AUC) = 0.677. Conclusions: In adults, clinical assessment alone using independent clinical signs and overall clinical impression does not allow a reliable diagnosis of PTA, even when performed by an otolaryngologist. CT is reliable in diagnosing PTA and, whenever available, should be the examination method of choice for diagnosing PTA, especially by a non-specialist.

Rosai-Dorfman disease is a non-Langherans cell histiocytosis typically revealed by lymphadenopathy. Extranodal involvement occurs in 43% and most commonly involves the head and neck, skin, and bones. Few reports have described laryngeal lesions. We report the case of a Rosai-Dorfman disease in a 27-year-old female, presenting as an obstructing transglottic mass. We provide the results of the MRI and PET-scanner examination. As the treatment relies on surgical excision and the diagnosis depends on pathological examination, we also detail the analysis results that followed the surgical resection. This report highlights the necessity to consider Rosai-Dorfman disease as a potential diagnosis in case of a laryngeal submucosal mass.