1. Is this adequate? 

This is usually asked by the procedurist during the rapid on-site evaluation (ROSE) process. In this case, there are clearly lesional cells in the core biopsy imprint. However, knowing that this will probably require ancillary testing for the definitive diagnostic workup, it would be best to ask for another one or two cores, if possible, from the same needle tract. 

2. What is the diagnosis?

Clinicians often chase for a diagnosis minutes after we receive the specimen. it is thus important to know what information we can provide that is helpful (eg. adequacy, lymphoid vs non-lymphoid) ]. We must, however, be careful not to provide inaccurate information.

Adequacy – discussed above. 

Lymphoid – In many instances, with careful attention to the cytology, it is possible to distinguish between lymphoid vs non-lymphoid lesions.

Run through your DDx first.

In this location and age group, possibilities include Lymphoma (mediastinal large B cell lymphoma, Hodgkin lymphoma and Lymphoblastic lymphoma); germ cell tumour; thymoma  (patients may be a little older usually)..

Always check other relevant investigations (eg. serum BHCG , AFP, LDH etc).

Features favoring lymphoma:

• Dispersed cells
• Presence of numerous lymphoglandular bodies in the background
• Features specific to above named lymphomas 

Lymphoglandular bodies are extremely helpful and are most readily appreciated in air-dried smears. 

Germ cell tumours vary widely in morphology:

• Seminoma – Large, relatively dispersed polygonal cells with round to irregular nuclei, prominent nucleoli and fairly abundant pale to vacuolated cytoplasm, admixed with many lymphocytes and sometimes small epithelioid granulomas. May have  reticular appearing tigroid background (due to glycogen)
• Yolk sac tumour, Embryonal carcinoma, Choriocarcinoma – Appear more cohesive and pleomorphic, resemble carcinoma or even adenocarcinoma. These may not be distinguishable from metastatic carcinoma from elsewhere, hence are difficult to confirm on morphology alone as germ cell tumours. 

Smears show numerous lesional cells which are fairly dispersed. No true cohesion or syncytial tissue fragments are seen. 

The cells are large, polygonal and contain large nuclei with variably prominent nucleoli. There is a moderate amount of pale to finely vacuolated cytoplasm. Some of the cells appear as bare nuclei.

Small lymphocytes are noted admixed with the lesional cells. The tumour cells are many times larger than the lymphocytes. No lymphoglandular bodies are seen in the background. no granulomas are identified.

Diagnosis: Seminoma 

This was confirmed on histology and ancillary tests.