BH: A 50-year-old male presented with many bilateral LNs in the neck. Clinical preliminary diagnosis was lymphoma or metastasis. An assessment of the patient's file before the FNA MRI report revealed a description of a 22 mm × 18 mm asymmetrical mass lesion in the nasopharynx. Unfortunately, this information was not indicated on the FNA requisition form. US findings: the radiologist detected many conglomerated LNs in the right and left sides of the neck during the US before the FNA. An FNA was performed from the largest LNs located at the left and right supraclavicular regions, which were18 mm × 10 mm and 30 mm × 18 mm in size, respectively. Cytologic findings: malignant tumor cells were observed individually or in scattered groups on a lymphoid background and appeared reactive. Thin fusiform particles were detected inside the nucleus in some cells in malignant clusters []. Cytologic diagnosis: Undifferentiated malignant tumor. Comment: the cytologic differential included the metastasis of head/neck-associated carcinoma and Hodgkin's lymphoma due to atypical mononuclear cells in the reactive lymphoid background. Histopathology: the nasopharyngeal biopsy showed undifferentiated nasopharyngeal carcinoma.\nTHM: (1) Metastasis in the LNs in undifferentiated carcinoma of the nasopharynx involves diagnostic challenges during the FNA.[] This condition may be confused with other nonkeratinized carcinoma metastases and lymphomas (especially Hodgkin's lymphoma). (2) Bizarre cells observed in undifferentiated nasopharyngeal carcinoma may resemble atypical mononuclear cells in Hodgkin's lymphoma (Hodgkin cells) and Reed–Sternberg cells [].
BH: US-FNA was requested for a 45-year-old male due to the presence of a palpable LN 2.5 cm below the sternocleidomastoid muscle in the right neck and 1 cm below the sternocleidomastoid muscle in the left neck. US-FNA was performed on these two lesions.\nCytologic findings: Epithelioid histiocytes and epithelioid histiocytic clusters forming granuloma-like structures were observed on a reactive lymphoid background. Undifferentiated malignant cells, which formed scattered groups around granulomatous structures, were also noted. Cytologic diagnosis: an undifferentiated malignant tumor that could be a metastasis of nasopharyngeal carcinoma/Hodgkin's lymphoma []. Histopathology: Nasopharyngeal carcinoma (nonkeratinized squamous cell type).