Introduction

• Common tumor type arising from glandular epithelial tissue.
• Prognosis: depends on site.
• Treatment: variable response to chemotherapy, surgery and/or radiation therapy which are the mainstays of treatment.
• In general malignant tumors/adenocarcinomas are much more common than benign adenomas/adenomas.
• Adenocarcinomas occur in the skin (sweat gland and ceruminous gland), oropharynx, nasal chamber, salivary gland, stomach, intestine, bile duct, gall bladder, mammary gland, larynx, trachea and lung.
• Adenomas occur in the skin (sweat gland), oropharynx, intestine, bile duct, mammary gland, kidney and thyroid gland.
• Adenocarcinomas are locally invasive and depending on site metastasize to local and distant sites
• Adenomas are non-invasive and do not metastasize.

Pathogenesis

Predisposing factors

General

• FeLV Feline leukemia virus unlikely to be associated with intestinal adenocarcinoma.

Pathophysiology

• Malignant adenocarcinomas/adenocarcinomas much more common.
• Adenocarcinomas are generally locally invasive and often metastasize to local and distant sites.
• Gastrointestinal metastatic disease is usually abdominal.

Tumor behavior

• Sweat gland and ceruminous gland adenocarcinomas - locally invasive, metastasis not common, to lungs, lymph nodes, liver, digits.
• Salivary gland adenocarcinoma Salivary gland: neoplasia - limited studies suggest cure with excision followed by radiation therapy.
• Mammary tumors  - 90% are adenocarcinoma and are aggressive. Systemic metastasis can occur - to lymph node, pleura, lung, liver, spleen, kidneys. Metastatic potential depends on size and histology.
• Pulmonary adenocarcinoma - aggressive tumor.
• Nasal adenocarcinoma - usually locally invasive but with low metastatic potential.
• Intestinal adenocarcinomas often extend into mesentery. Distant metastasis to lymph nodes, spleen, lungs or kidney common in small intestinal adenocarcinomas, less common in large intestine.

Timecourse

• Weeks/months.

Diagnosis

Treatment

Outcomes