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 41-year-old male presented with multiple LNs in the right neck; the largest ones were 32 mm × 20 mm in the right submandibular region and 35 mm × 15 mm and 25 mm × 20 mm in the right neck. A positron emission tomography-computed tomography (PET-CT) scan showed involvement with suspicions of malignancy in the stomach wall and the LNs. Clinical preliminary diagnosis: stomach cancer with metastasis to the neck LNs. Cytologic findings: US-FNA was used in the three LNs in the neck. Similar characteristics were observed in all LNs: Pleomorphic malignant cells represented individually in some areas and forming clusters in others were formed on a partially eosinophilic reactive lymphoid background. The nuclei of malignant cells were large, and the cytoplasm was wide and vacuolated. Enlarged nucleoli were observed in some cells []. Cytologic diagnosis: Undifferentiated malignant tumor cells. Comment: malignant cells with a pleomorphic nature were observed admixed with reactive lymphoid cells and eosinophilia. The cellular characteristics resembled adenocarcinoma, as suspected clinically. However, due to multiple large LNs that were identified during US, pleomorphic cells also resembled “lacunar cells” seen in “nodular sclerosing type Hodgkin's lymphoma.” Histopathology: Nodular sclerosing type Hodgkin's lymphoma.\nTHM: (1) Despite the suspicion of “gastric cancer” due to the PET-CT results, the radiologist warned about multiple LNs during the US-FNA. (2) Lacunar cells from Hodgkin's lymphoma obtained through FNA may be confused with carcinoma, melanoma, germ cell tumor, and sarcoma.[]