Thread by @TristanRutland7

Toe, adult

#Dermpath #BSTpath #Pathtwitter #Pathresidents

Based on the images only, what is your initial impression?

⚕️Diagnosis:

🔬Digital papillary adenocarcinoma

🙏Colleague’s case

Question:

Which of the following is correct about these tumours?

1/ These tumours have a wide age range but are more common in men.

2/ They are more common in the fingers.

3/ Presentation with metastatic disease is rare.

4/ Metastasis are usually a late occurrence (up to 20 years)

pubmed.ncbi.nlm.nih.gov/23026931/

Question:

These tumours are thought to arise from?

5/ Electron microscopy showed 3 cell types ➡️clear, dark, & myoepithelial cells.

6/ The dark (epithelial cells) showed secretory activity and with only sparse tonofilaments.

7/ This is keeping with eccrine glandular differentiation.

pubmed.ncbi.nlm.nih.gov/3301927/

Question:

Histologically, this tumours shows which sort of pattern?

8/ They are usually multinodular and can show a mixture of patterns:

🟦Solid (can be cribriform)
⭕️Cystic
🌿Papillary (true or psuedo)

9/ Myoepithelial cells may be present (positive for p63, SMA).

10/ Histology is NOT a predictor of behavior!

journals.lww.com/ajsp/Fulltext/…

Last question

True or false?

A history of trauma is associated with these tumours.

11/ A study of 67 cases showed that antecedent trauma was noted in 9.

12/ So does the trauma bring attention to the lesion or causes it due to some weird inflammatory/regenerative effect?? Does anyone know? (I certainly do not!)

pubmed.ncbi.nlm.nih.gov/10843279/

13/ Lastly, check out this tweet in regards to an important DDx:

Acral hidroadenoma vs digital papillary adenocarcinoma

https://twitter.com/JCandidoXavier/status/1373638029592702978?s=20