Subcentimeter Lymph Nodes Research Articles

Applications of diffusion-weighted magnetic resonance imaging in head and neck squamous cell carcinoma

In the head and neck, squamous cell carcinoma is one of the most common tumour types. Currently, the primary imaging modalities for initial locoregional staging are computed tomography and-to a lesser extent-magnetic resonance imaging, whilst [(18)F]fluorodeoxyglucose (FDG) positron emission tomography has additional value in the detection of subcentimetric metastatic lymph nodes and of tumour recurrence after chemoradiotherapy (CRT). However, dependency on the morphological and size-related criteria of anatomical imaging and the limited spatial resolution and FDG avidity of inflammation in metabolic imaging may reduce diagnostic accuracy in the head and neck. Diffusion-weighted magnetic resonance imaging (DWI) is a noninvasive imaging technique that measures the differences in water mobility in different tissue microstructures. Water mobility is likely influenced by cell size, density, and cellular membrane integrity and is quantified by means of the apparent diffusion coefficient. As such, the technique is able to differentiate tumoural tissue from normal tissue, inflammatory tissue and necrosis. In this article, we examine the use of DWI in head and neck cancer, focussing on technique optimization and image interpretation. Afterwards, the value of DWI will be outlined for clinical questions regarding nodal staging, lesion characterization, differentiation of post-CRT tumour recurrence from necrosis and inflammation, and predictive imaging towards treatment outcome. The possible consequences of adding DWI towards therapeutic management are outlined.

Pediatric squamous cell carcinoma: Case report and literature review

Describe a rare pediatric malignancy. Discuss the clinical, diagnostic, and therapeutic differences between squamous cell carcinoma (SCC) of the adult and pediatric population. Case report including a detailed radiological and histopathologic analysis and review of the literature. A case report is described from a tertiary care university hospital. Histopathologic assessment and radiological details are reviewed. A literature review of the background, incidence, disease course, and treatment options are presented. This case report presents a 6-year-old male with a 2-month history of an enlarging oral lesion. The patient denied dysphagia, pain, weight loss, bleeding, or loosening of the teeth. Biopsy demonstrated invasive, well-differentiated, exophytic squamous cell carcinoma with perineural and angiolymphatic invasion. Computed tomography and magnetic resonance imaging demonstrated a 2.7 x 3.0 cm poorly marginated infiltrative mass involving the gingival aspect of the superior alveolar ridge and the adjacent bony marrow, primarily to the right of midline. Multiple small subcentimeter lymph nodes were also identified in the bilateral level II to V posterior cervical triangles bilaterally. Pediatric SCC of the oral cavity is indeed a rare entity; however, its presence in the pediatric population should not be ignored. This case report describes the occurrence of SCC in the oral cavity of a 6-year-old male patient, the youngest case ever reported, and is a reminder that a multidisciplinary approach tailored to pediatric individuals is essential to obtain clear diagnoses and appropriate treatment plans.

Head and Neck Squamous Cell Carcinoma: Value of Diffusion-weighted MR Imaging for Nodal Staging

To evaluate diffusion-weighted (DW) magnetic resonance (MR) imaging, as compared with turbo spin-echo MR imaging, for the detection of nodal metastases in head and neck squamous cell carcinoma (HNSCC). The study was approved by the ethics committee, and patients gave written informed consent. Before undergoing surgery, 33 consecutive patients underwent 1.5-T MR imaging, including DW imaging performed with a wide range of b values (0-1000 sec/mm(2)). The apparent diffusion coefficients (ADCs) of lymph nodes 4 mm or greater in short-axis diameter depicted on images obtained with b values of 0 and 1000 sec/mm(2) were calculated. After topographic correlation, the lymph nodes were evaluated microscopically with prekeratin immunostaining. The optimal ADC thresholds for discriminating between metastatic and benign lymph nodes were determined. The sensitivity, specificity, and accuracy of DW imaging were calculated separately-on per-lymph-node and per-neck-level bases-for all lymph nodes and for supracentimeter and subcentimeter lymph nodes and were compared with corresponding turbo spin-echo MR imaging values. Correlation of histopathologic and radiologic findings was possible for 301 lymph nodes. The ADC derived from the signal intensity averaged across images obtained with b values of 0 and 1000 sec/mm(2) (ADC(b0-1000)) was 1.19 x 10(-3) mm(2)/sec +/- 0.22 (standard deviation) for benign lymph nodes and 0.85 x 10(-3) mm(2)/sec +/- 0.27 for malignant lymph nodes (P < .0001). With an optimal ADC(b0-1000) threshold of 0.94 x 10(-3) mm(2)/sec, 84% sensitivity, 94% specificity, and 91% accuracy for differentiation of malignant versus benign status of each lymph node and 94% sensitivity, 97% specificity, and 97% accuracy for differentiation at each neck level were achieved. Compared with turbo spin-echo imaging, DW imaging had higher sensitivity (76% vs 7%) but slightly lower specificity (94.0% vs 99.5%) for detection of subcentimeter nodal metastases. DW imaging performed with ADC(b0-1000) values had higher accuracy than turbo spin-echo MR imaging in nodal staging, providing added value in the detection of subcentimeter nodal metastases.

Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a rare skin neuroendocrine carcinoma frequently occurring in the head and neck area. It is known for being a locally aggressive disease with a high incidence of regional and distant metastases. Accurate initial staging and close surveillance are critical in the management of the disease. Two cases of MCC are reported in which fluorine-18-fluorodeoxyglucose positron emission tomography (FDG PET) imaging has been beneficial in directing management and predicting clinical course. Pretreatment FDG PET scans detected metastatic disease in subcentimeter lymph nodes that were not appreciated in initial computed tomography images. Posttreatment FDG PET scans predicted response to therapy with the level of FDG uptake correlating in both areas of complete response to treatment and areas of residual diseases. Finally, FDG PET imaging also detected the progression of the disease after initial treatment. FDG PET imaging is a very sensitive modality in staging, assessment of treatment response, and surveillance of MCC. Because of the rarity of MCC, multicenter study is warranted to accumulate enough cases to determine the sensitivity and specificity of FDG PET in staging and surveillance of MCC, and the impact on the management and treatment outcome.