Adenocarcinoma

Adenocarcinoma (lung). Pleural fluid specimen. Pap stain. (WC)

Adenocarcinoma (colorectal). Field stain. (WC)

Colorectal adenocarcinoma. H&E stain. (WC)

Adenocarcinoma is a form of cancer that arises from glandular tissue. Adenocarcinoma can arise in many sites.

Adenocarcinoma not otherwise specified, also adenocarcinoma NOS, is a non-specific malignant diagnosis that without further information is not very useful for treatment decisions.

Types of adenocarcinoma

Site specific

Below is an incomplete list of adenocarcinomas.

Gastrointestinal pathology

Esophagus

• Esophageal adenocarcinoma.

Stomach

• Gastric adenocarcinoma.

Duodenum

• Adenocarcinoma of the duodenum.

Ampulla of Vater

• Ampullary adenocarcinoma.

Pancreas

• Pancreatic ductal adenocarcinoma.

Gallbladder

• Gallbladder adenocarcinoma.

Colon and rectum

• Colorectal adenocarcinoma.

Other

Lung

• Adenocarcinoma of the lung.

Salivary gland

• Polymorphous low-grade adenocarcinoma.
• Basal cell adenocarcinoma.

Gynecologic pathology

Ovary

• Ovarian clear cell adenocarcinoma.
• Mucinous adenocarcinoma of the ovary.

Endometrium

• Endometrioid endometrial adenocarcinoma.

Cervix

• Endocervical adenocarcinoma.
• Villoglandular adenocarcinoma of the cervix.
• Minimal deviation adenocarcinoma of the uterine cervix.

Genitourinary pathology

Prostate

• Prostatic adenocarcinoma, not otherwise specified.
• Prostatic ductal adenocarcinoma.
• PIN-like prostatic ductal adenocarcinoma.

Testis

• Adenocarcinoma of the rete testis.

Urinary bladder

• Adenocarcinoma of the urinary bladder.
• Urachal adenocarcinoma.

General type

• Clear cell adenocarcinoma.
• Mucinous adenocarcinoma.

Microscopic (generic)

Features:

• Gland forming - round/ovoid/tubular spaces.
• Eccentric nucleus.
• Moderate cytoplasm +/- vacuoles.
• +/-Prominent nucleolus.
• +/-Nuclear atypia - dependent on type/site.

DDx:

• Carcinoma (poorly differentiated).
• Sarcoma, esp. epithelioid sarcomas.
• Benign glands.
  • Endometriosis.
  • Endosalpingiosis.
  • Adenomyosis.

Grading

Adenocarcinomas are often graded by their glandular component:

• Grade 1: >95% of tumour glandular.
• Grade 2: 50-95% of tumour glandular.
• Grade 3: <50% of tumour glandular.

Special grading systems exists based on the primary site; examples are:

• Nottingham grade for invasive breast cancer
• WHO grade groups for prostate cancer.

See also

• Carcinoma.
• Adenocarcinoma in situ.
• Pathologic fracture.