A Neck Swelling

Clinical history: 64 Chinese Male. Smoker. Noticed left neck swelling for 1 month.

Physical examination revealed matted left level II – III cervical lymph nodes

1. Air-dried smear (Hemacolor)

2. Alcohol-fixed smear (Pap)

1. You’ve just screened this case. What would you do next?

Discussion

The smears clearly show a population of malignant cells.

The cytomorphologic features (large atypical cells, macronucleoli, syncytial architecture, relative paucity of lymphoglandular bodies) suggest a non-lymphoid malignancy.

Hence, a metastatic poorly differentiated / undifferentiated carcinoma is high on the list, this being an Asian patient.

It would be prudent to check the clinical notes to see if the post-nasal space has been examined, and, if so, whether there is an accompanying biopsy. If there is, a morphologic comparison could be made of both samples, as the node likely represents metastatic nasopharyngeal carcinoma.

Any necessary stains can be performed on the biopsy (eg. EBER-ISH).

Each report (cytology and histology) should contain a reference to the other.

If there is no accompanying PNS biopsy, then one could see if there is available material from the FNA for a cell block, and perform EBER-ISH on it.
If no cell block is available, it should be signed out as metastatic poorly differentiated carcinoma with appropriate comments to direct further investigation (see sample diagnosis below).

2. What is the diagnosis?

Description and Diagnosis

Highly cellular smears show numerous moderately sized 3 dimensional clusters of atypical cells. The clusters exhibit scalloped borders. The cells contain moderately pleomorphic nuclei with relatively smooth nuclear membranes, prominent nucleoli and raise N/C ratios. The cytoplasm varies from fairly pale to dense, and in some areas, exhibits a two-toned appearance with a finely bubbly outer edge. The nuclei are fairly centrally located within the cells. Some cell-in-cell arrangements are noted. Windows are not readily identified. No definite population of benign mesothelial cells is seen.

Diagnosis: Left pleural effusion: Malignant mesothelioma

Note: Being a relatively uncommon diagnosis in most areas, the first time diagnosis of malignant mesothelioma should be made in the context of clinicopathologic correlation (history, imaging) and with immunocytochemical corroboration.

Here is the video demonstration with voiceover.

Lymph Node 3

A Neck Swelling