Submucosal small-cell neuroendocrine carcinoma of the larynx detected using 18F-fluorodeoxyglucose positron emission tomography/computed tomography: A case report and review of the literature

PET/CT Evaluation of Head and Neck Cancer of Unknown Primary

The diagnosis of carcinoma of unknown primary in the head and neck is made when there is a metastasis but no primary lesion is identified after physical exam and diagnostic CT or MR imaging. PET/CT is the first step in searching for a primary lesion, followed by more invasive techniques such as endoscopy and surgery. Knowledge of the different tumor histologic types, preferential locations of nodal spread, imaging pitfalls, and other special considerations such as cystic metastases can be helpful in the ultimate identification of primary tumors, which leads to improved overall patient survival.

Primary poorly differentiated small cell type neuroendocrine carcinoma of the hypopharynx

The incidence of primary poorly differentiated neuroendocrine carcinoma (PDNC) of the hypopharynx iŝ4%. However, the disease pathogenesis, natural history, and prognostic factors remain poorly understood. We report the case of a 66-year-old man who presented with multiple metastases from primary PDNC of the hypopharynx. Physical examination revealed ã3×4 cm left cervical mass located at the level III, with tenderness and an unclear boundary. Laryngoscopy revealed a large mass arising from the posterior hypopharynx; glottis and vocal cord movements were invisible. After consultation with our head and neck oncological multidisciplinary team, diagnosis and specific treatment plan were made. Under general anesthesia, a biopsy sample was obtained via suspension laryngoscopy. Routine pathology revealed small cell carcinoma. Immunohistochemical staining identified neoplastic cells that were positive for cytokeratins, CD56, chromogranin A, and synaptophysin. The Ki-67 mitotic index approached 80%. These findings confirmed hypopharyngeal PDNC, and chemotherapy was prescribed. After 7 months, the tumor metastasized to the left side of the anterior chest wall, bilateral lungs, left liver, and skeleton. The soft tissue of the chest wall was biopsied, and pathology revealed PDNC. Subsequent examinations over the next 4 months confirmed multiple liver metastatic lesions. The patient succumbed to the cancer progression a month later. Here, we systematically review the clinical manifestations, pathogenesis, prognostic factors, and treatment of the disease. In conclusion, patients always have a poor prognosis due to a lack of optimal treatment.

Collision carcinoma of squamous cell carcinoma and small cell neuroendocrine carcinoma of the larynx: A case report and review of the literature

BACKGROUND

Collision carcinoma is rare in clinical practice, especially in the head and neck region. In this paper, we report a case of squamous cell carcinoma (SCC) and neuroendocrine carcinoma (NEC) colliding in the larynx and review 12 cases of collision carcinoma in the head and neck to further understand collision carcinoma, including its definition, diagnosis, and treatment.

CASE SUMMARY

A 61-year-old man presented with a 1-year history of hoarseness. Contrast-enhanced magnetic resonance imaging of the larynx revealed that the right vocal cord had a nodule-like thickening with obvious enhancement. Laryngoscopy revealed a neoplasm on the right vocal cord, and a malignant tumor was initially considered. A frozen section of right vocal cord was performed under general anesthesia. The pathological result showed a malignant tumor in the right vocal cord. The tumor was excised with a CO₂ laser (V_c type). Routine postoperative pathology showed moderately differentiated SCC with small cell NEC in the right vocal cord. No metastatic lymph nodes or distant metastases were found on postoperative positron emission tomography/computed tomography. Because of the coexistence of SCC and NEC, the patient received adjuvant chemotherapy and radiotherapy. The patient was followed for 8 mo, and no recurrence or distant metastasis was found.

CONCLUSION

The treatment of collision carcinoma in the head and neck region is uncertain due to the small number of cases.

Cutaneous and Subcutaneous Metastases From Atypical Laryngeal Carcinoids: Case Report and Review of the Literature

The incidence of cutaneous and subcutaneous metastases from atypical laryngeal carcinoids is approximately 20%. However, the pathogenesis and natural history of, and prognostic factors for, the condition remain poorly understood. We reported a 54-year-old female presented with cutaneous and subcutaneous metastases from atypical laryngeal carcinoid. Laryngoscopy revealed a 0.5 × 1.5-cm reddish mass on the laryngeal surface of the epiglottis. Under general anesthesia, a biopsy sample was obtained via suspension laryngoscopy. Routine pathology revealed atypical laryngeal carcinoid. Immunohistochemical staining of the sections of primary tumor was positive for cytokeratin, chromogranin A, synaptophysin, hypoxia-inducible factor-1α, P53, and CD56. GLUT-1, p-Akt, and PI3K were negative. The Ki-67 index was 15%. Supraglottic laryngectomy and selective right-neck dissection were performed. After 6 months, the patient complained of pain in the right wall of the chest; multiple cutaneous and subcutaneous nodules were evident at that site and in the abdomen. An abdominal nodule was biopsied and pathology revealed that the atypical metastatic carcinoid had metastasized to both cutaneous and subcutaneous areas of the abdomen. Chemotherapy was then prescribed. Currently, the intrathecal drug delivery system remains in place. No local recurrence has been detected. Furthermore, we systematically reviewed clinical manifestations of the disease, pathogenesis, prognostic factors, and treatment. The metastasis rate (cutaneous and subcutaneous) was approximately 12.2%. Thirty patients (62.5%) with cutaneous and subcutaneous metastases exhibited contemporaneous lymph node invasion. The 3-, 5-, and 10-year survival rates were 44.0%, 22.0%, and 13.0%, respectively. The prognosis of patients with atypical laryngeal carcinoids was poor. Relevant prognostic factors included the level of p53, human papilloma virus status, certain hypoxic markers, and distant metastasis. No optimal treatment for such metastases has yet been defined.