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: A 72-year-old female presented with a mass in the neck that had been present for 1 month. A 35 mm × 20 mm LN was observed in the left submandibular region during US, while 24 mm × 16 mm and 26 mm × 15 mm nodules were observed in the right thyroid isthmus and the left lobe, respectively. Clinical prediagnosis included lymphoma and metastasis; US-FNA was performed on all three lesions. Cytologic findings: LN: high numbers of pleomorphic, multinuclear, bizarre and undifferentiated cells were noted in the left submandibular mass []. Thyroid nodules: The findings were compatible with “adenomatous nodule” (FNA was performed in the same session to exclude thyroid malignancy). Cytologic diagnosis of the submandibular mass was “undifferentiated pleomorphic malignant tumor.” Histoimmunopathology: Anaplastic large cell lymphoma. THM: The detection of many multinuclear, large, “bizarre” cells led us to consider the presence of three lesions during the differential diagnosis: Anaplastic large cell lymphoma, melanoma and anaplastic carcinoma/sarcoma.