Adenocarcinoma NOS

ADENOCARCINOMA NOS

  • Tumor with glandular or ductal differentiation that does not have specific histomorphologic features of specific type of carcinoma.
  • Accounts 9% of all salivary gland tumors.
  • Occurs at any age group with slight female predilection
  • Both major and minor salivary glands are affected. Parotid is most commonly affected. Among the minor salivary glands palatal glands are more commonly affected.
  • Clinical features – presents as asymptomatic mass.
  • Gross – tumor is circumscribed and may have  irregular borders. cut surface is gray white with areas of hemorrhages and necrosis.
  • Microscopic findings –
    • Tumor cells are arranged in numerous pattern like small nests, islands, ramifying cords, tubules or densely cellular solid sheets. glandular pattern is common to all of them
    • Depending upon cytologic atypia, low, intermediate and high grade tumors are categorized
    • Ductal or glandular differentiation is evident in low and intermediate grade tumors and it is more subtle in high grade tumors.
    • High grade tumors show increased mitotic activity and necrosis
    • Perineural and perivascular growth are common
  • Differential diagnosis
    • Adenomas
    • Polymorphous low grade adenocarcinoma
  • Treament
    • Surgery is treatment of choice
    • Adjuvant post operative radiotherapy is inducted in intermediate and high grade tumors that are of advanced clinical stage. Distant metastasis is common and lung is commonly affected

Adenocarcinoma NOS: Circumscribed tumor with sheets of tumor cells (on the right) and normal parotid acini (on the left) (H&E,X50)

Adenocarcinoma NOS: Circumscribed tumor with sheets of tumor cells (on the top) and normal parotid acini (on the lower left) (H&E,X100)

Adenocarcinoma NOS (high grade): Sheets of tumor cells arranged in glandular pattern with necrotic material. Intervening stroma shows hyalinization (H&E,X100)

Adenocarcinoma NOS (High grade): Sheets of tumor cells arranged in glandular pattern with necrotic material. Intervening stroma shows hyalinization (H&E,X100)

Adenocarcinoma NOS: Tumor cells arranged in nesting pattern (H&E, 100)

Adenocarcinoma NOS: Tumor cells arranged in organoid pattern with nests of tumor cells separated by fibrous septa. Tumor cells have round to oval nuclei . Some of them show prominent nucleoli. Cells have moderate amount of cytoplasm (H&E, 400).

Adenocarcinoma NOS: Tumor cells arranged in organoid pattern with nests of tumor cells separated by fibrous septa. Tumor cells have round to oval nuclei . Some of them show prominent nucleoli. Cells have moderate amount of cytoplasm (H&E, 400).

Adenocarcinoma NOS: Tumor with tumor cells showing perineural invasion (H&E,X100)

Adenocarcinoma NOS:Tumor with tumor cells showing perineural invasion (H&E,X100)