These tumors are referred to as Anaplastic or Undifferentiated carcinomas.

There are a large number of rare subtypes of anaplastic, undifferentiated carcinoma.

Undifferentiated carcinoma.

The differential diagnosis includes carcinoma ex-pleomorphic adenoma and undifferentiated carcinoma.

Type 2a (II) is keratinizing undifferentiated carcinoma.

Rare subtypes include glandular tumors, carcinoid tumors, and undifferentiated carcinomas.

Type 2b (III) is nonkeratinizing undifferentiated carcinoma.

Esthesioneuroepithelioma, sometimes confused with undifferentiated carcinoma or undifferentiated lymphoma, arises from the olfactory nerves.

In those patients with squamous cell or undifferentiated carcinoma, tonsillectomies have been recommended and should be considered if the tonsils have not been previously removed.

Silverman C, Marks JE: Metastatic cancer of unknown origin: epidermoid and undifferentiated carcinomas.

None Sinonasal undifferentiated carcinoma (SNUC) is a rare cancer of the nasal cavity and/or paranasal sinuses.

Type 1 is squamous cell carcinoma, type 2 is nonkeratinizing carcinoma, and type 3 is undifferentiated carcinoma.

Large cell carcinomas, sometimes referred to as undifferentiated carcinomas, are the least common type of NSCLC, accounting for 10%-15% of all lung cancers.

Sinonasal undifferentiated carcinoma, abbreviated SNUC, is a rare aggressive type of cancer that arises from epithelium of the nose or sinuses.

If the biopsy is an undifferentiated carcinoma (in particular, a lymphoepithelioma), the most probable primary site is in Waldeyer ring; for example, the nasopharynx, base of tongue, or tonsil.

Frank DK, Cheron F, Cho H, et al.: Nonnasopharyngeal lymphoepitheliomas (undifferentiated carcinomas) of the upper aerodigestive tract.

Stanley RJ, Weiland LH, DeSanto LW, et al.: Lymphoepithelioma (undifferentiated carcinoma) of the laryngohypopharynx.

Azli N, Armand JP, Rahal M, et al.: Alternating chemo-radiotherapy with cisplatin and 5-fluorouracil plus bleomycin by continuous infusion for locally advanced undifferentiated carcinoma nasopharyngeal type.

Other exocrine cancers include adenosquamous carcinomas, signet ring cell carcinomas, hepatoid carcinomas, colloid carcinomas, undifferentiated carcinomas, and undifferentiated carcinomas with osteoclast-like giant cells.

Grade 4, or undifferentiated carcinoma: these carcinomas bear no significant resemblance to the corresponding parent cells and tissues, with no visible formation of glands, ducts, bridges, stratified layers, keratin pearls, or other notable characteristics consistent with a more highly differentiated neoplasm.