Short power list

The short power list is a short differential diagnosis for the most common specimens. This is list is written for junior residents and should serve as a starting point if one has no clue about the differential diagnosis for the site. It assumes the specimen comes from an adult.

Bone

General

Benign:

• Aneurysmal bone cyst.
• Osteoid osteoma.

Malignant:

• Metastatic carcinoma.
• Plasma cell neoplasm.
• Osteosarcoma.
• Ewing sarcoma.

Femoral head

Benign:

• Osteoarthritis.
• Avascular necrosis of the femoral head.
• Rheumatoid arthritis.

Uncommon - benign (fracture):

• Trauma.
• Osteoporosis.

Uncommon - benign pediatric:

• Slipped femoral capital epiphysis (SFCE).
• Legg–Calvé–Perthes syndrome.

Uncommon - malignant (fracture):

• Metastasis.

Breast pathology

Benign:

• Normal.
• Fibrocystic change.
• Fibroadenoma.
• Columnar cell change.
• Sclerosing adenosis.

Malignant:

• DCIS.
• LCIS.
• Ductal carcinoma.
• Lobular carcinoma.
• Tubular carcinoma.

Uncommon benign/malignant:

• Phyllodes tumour.

Cardiovascular pathology

General

• Thrombosis (embolism).
• Vasculitis.

Uncommon:

• Amyloid deposition.
• Hyperplastic arteriolosclerosis.

Aorta

• Atherosclerosis.

Uncommmon:

• Cystic medial degeneration.

Aortic valve

• Calcific aortic stenosis.

Uncommon:

• Infective endocarditis.
• Myxomatous degeneration.
• Papillary fibroelastoma.

Mitral valve

• Rheumatic heart disease.

Uncommon:

• Myxomatous degeneration.
• Infective endocarditis.

Heart

• Atrial myxoma.

Uncommon - benign:

• Lipoma.
• Rhabdomyoma.

Uncommon - malignant:

• Pleomorphic undifferentiated sarcoma.
• Angiosarcoma.

Dermatopathology

Benign - non-melanocytic:

• Epidermal inclusion cyst.
• Lipoma.
• Dermatofibroma.
• Dermal scar.

Benign melanocytic lesions:

• Intradermal nevus.
• Junctional nevus.
• Congenital nevus.
• Clark nevus.
• Spitz nevus.

Malignant:

• BCC.
• SCC.
• Malignant melanoma.
• DFSP.

Endocrine pathology

Thyroid gland

Benign:

• Nodular hyperplasia.
• Lymphocytic thyroiditis.

Malignant:

• Papillary thyroid carcinoma, follicular variant.

Uncommon - malignant:

• Papillary thyroid carcinoma, columnar cell variant.
• Papillary thyroid carcinoma, tall cell variant.
• Medullary thyroid carcinoma.
• Anaplastic thyroid carcinoma.

Adrenal gland

Benign:

• Adrenal cortical adenoma.

Malignant:

• Adrenal cortical carcinoma.
• Pheochromocytoma.

Gastrointestinal pathology

Appendix

Benign:

• Appendicitis.
• Periappendicitis.
• Crohn's disease.
• Normal.

Neoplasm:

• Neuroendocrine tumour.
• Low-grade appendiceal mucinous neoplasm (LAMN).

Malignant:

• Mucinous adenocarcinoma.

Gallbladder

Benign:

• Cholelithiasis.
• Cholesterolosis.
• Acute cholecystitis.
• Chronic cholecystitis.

Uncommon - pre-malignant:

• Intestinal metaplasia.

Uncommon - malignant:

• Adenocarcinoma.

Gastrointestinal polyp

Benign:

• Normal.
• Hyperplastic polyp.
• Inflammatory pseudopolyp (inflammatory bowel disease).

Pre-malignant:

• Tubular adenoma.
• Villous adenoma.
• Tubulovillous adenoma.
• Sessile serrated adenoma.

Uncommon - pre-malignant:

• Traditional serrated adenoma.

Stomach

Benign:

• Helicobacter pylori gastritis.
• Intestinal metaplasia.
• Chronic gastritis.
• Acute gastritis.

Pre-malignant:

• Gastric dysplasia.

Malignant:

• Adenocarcinoma, intestinal type.
• Signet-ring cell carcinoma.
• GIST.

Duodenum

Benign:

• Normal.
• Celiac disease.

Pre-malignant:

• Tubular adenoma.

Malignant:

• Adenocarcinoma.

Uncommon benign:

• Giardiasis.
• Whipple disease.
• MAI infection.

Liver

Benign:

• Steatosis.
• Steatohepatitis.
• Hepatitis B.
• Hepatitis C.

Malignant:

• Metastatic adenocarcinoma.
• Hepatocellular carcinoma.

Uncommon benign:

• Autoimmune hepatitis.
• Primary sclerosing cholangitis, esp. in the context of UC.
• Primary biliary cirrhosis.
• Wilson's disease.
• Hereditary hemochromatosis.
• Alpha-1 antitrypsin deficiency.

Uncommon malignant:

• Cholangiocarcinoma.

Genitourinary pathology

Tumour kidney

Benign:

• Normal.
• Renal oncocytoma.
• Angiomyolipoma.
• Papillary adenoma.

Malignant:

• Clear cell renal cell carcinoma.
• Papillary renal cell carcinoma.
• Chromophobe renal cell carcinoma.
• Urothelial carcinoma.

Uncommon - benign:

• Xanthogranulomatous pyelonephritis.

Medical kidney

• Diabetic nephropathy.
• Systemic lupus erythematosus.

Prostate gland

Benign:

• Normal.
• Chronic inflammation.
• Acute inflammation.
• Benign prostatic hyperplasia (prostectomy diagnosis only).

Malignant:

• Acinar adenocarcinoma.

Uncommon - malignant:

• Ductal adenocarcinoma.
• Urothelial carcinoma.

Urinary bladder

Benign:

• Inverted urothelial papilloma.
• Cystitis cystica.

Pre-malignant/malignant:

• Urothelial dysplasia.
• Low grade papillary urothelial carcinoma.
• High grade papillary urothelial carcinoma.
• Flat urothelial carcinoma.

Uncommon - benign:

• Malakoplakia.
• Nephrogenic adenoma.

Gynecologic pathology

Uterus

Benign:

• Fibroids.
• Adenomyosis.
• Atrophy.
• Uterine prolapse.
• Proliferative phase endometrium.
• Secretory phase endometrium.

Pre-malignant:

• Complex endometrial hyperplasia.

Malignant:

• Endometrial carcinoma.
  • Endometrioid.
  • Mucinous.
  • Serous.

Uncommon - benign:

• Decidua (change of pregnancy).

Uncommon - malignant:

• Clear cell carcinoma.
• Carcinosarcoma.

Cervix - cytology

Benign:

• Normal.
• Candida.
• Endometrial cells.
• Atrophy.

Pre-malignant/malignant:

• LSIL.
• HSIL.
• Squamous cell carcinoma.
• Adenocarcinoma.

Uncommon - benign:

• HSV changes.
• Trichomonas.

Ovary

Benign:

• Serous cystadenoma.
• Mucinous cystadenoma.
• Mature teratoma.
• Endometriosis.

Malignant:

• Serous carcinoma.
• Endometrioid carcinoma.
• Mucinous carcinoma.

Uncommon - malignant:

• Dysgerminoma.

Fallopian tube

Benign:

• Paratubal cyst.
• Tubo-ovarian abscess.
• Salpingitis.
• Ectopic pregnancy.
• Adenomatoid tumour.

Malignant:

• Serous carcinoma.

Uncommon - benign:

• Salpingitis isthmica nodosa.

Head and neck

General

Benign:

• Sinonasal papilloma.
• Vocal cord nodule.

Malignant:

• Squamous cell carcinoma.
• Nasopharyngeal carcinoma.

Uncommon - malignant:

• Paraganglioma (carotid body tumour).

Salivary gland

Benign:

• Pleomorphic adenoma.
• Warthin tumour.

Malignant:

• Mucoepidermoid carcinoma.
• Adenoid cystic carcinoma.

Uncommon benign:

• Benign lymphoepithelial cyst.
• Basal cell adenoma.
• Canalicular adenoma.
• Oncocytoma.

Uncommon malignant:

• Acinic cell carcinoma.
• Polymorphous low grade adenocarcinoma.
• Carcinoma ex pleomorphic adenoma.
• Salivary duct carcinoma.
• Hyalinizing clear cell carcinoma.

Lymph node

Benign:

• Normal/resting.
• Follicular hyperplasia.

Malignant:

• Metastasis, esp. carcinoma.
• Chronic lymphocytic leukemia.
• Follicular lymphoma.
• Diffuse large B cell lymphoma.
• Nodular sclerosis Hodgkin lymphoma.
• Mixed cellularity Hodgkin lymphoma.
• MALT lymphoma.

Pulmonary pathology

Benign:

• Normal.

Malignant:

• Adenocarcinoma.
• Squamous carcinoma.
• Small cell carcinoma.

Uncommon - benign:

• Tuberculosis.
• Sarcoidosis.
• Usual interstitial pneumonia.
• Solitary fibrous tumour - esp. pleural.

Uncommon - malignant:

• Mesothelioma.

Soft tissue

Benign:

• Lipoma.
• Hemangioma.
• Neurofibroma.

Malignant:

• Liposarcoma.
• Pleomorphic undifferentiated sarcoma.
• Chondrosarcoma.

Spleen

Benign:

• Trauma.
• Normal.
• Enlargement due to cirrhosis.

Malignant:

• Hairy cell leukemia.

See also

• Diagnosis.
• Long power list.