| Hyalinizing clear cell carcinoma | |
|---|---|
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| Micrograph of a hyalinizing clear cell carcinoma showing the characteristic clear cells and surrounding hyalinized stroma. H&E stain. | |
| Specialty | Oncology, ENT surgery |
Hyalinizing clear cell carcinoma (HCCC) is a rare malignant salivary gland tumour, with a good prognosis, that is usually found on the tongue or palate. [1]
HCCCs typically present as a painless mass in the mouth. [2]
HCCCs are diagnosed by examination of tissue, e.g. a biopsy.
HCCC consist of cells with abundant clear cytoplasm, arranged in cords, trabeculae or clusters in a hyalinized stroma. [3] Nuclear pleomorphism is usually minimal and mitoses are infrequently seen. [2]
Owing to their glycogen content, which explains the "clear" appearance under the microscope, tumour cells stain with PAS. Immunostains for S100 and smooth muscle actin (SMA) are typically negative, but positive for cytokeratins and epithelial membrane antigen (EMA).
HCCCs typically have a recurrent chromosomal translocation, t(12;22), involving the genes EWSR1 and ATF1. [4] The same translocation is seen in clear cell sarcoma.
The histologic differential diagnosis includes mucoepidermoid carcinoma (clear cell variant), acinic cell carcinoma (clear cell variant), epithelial-myoepithelial carcinoma and metastatic clear cell carcinoma.
They generally have a good prognosis. [5]
Adenoid cystic carcinoma is a rare type of cancer that can exist in many different body sites. This tumor most often occurs in the salivary glands, but it can also be found in many anatomic sites, including the breast, lacrimal gland, lung, brain, bartholin gland, trachea, and the paranasal sinuses.
Desmoplastic small-round-cell tumor (DSRCT) is an aggressive and rare cancer that primarily occurs as masses in the abdomen. Other areas affected may include the lymph nodes, the lining of the abdomen, diaphragm, spleen, liver, chest wall, skull, spinal cord, large intestine, small intestine, bladder, brain, lungs, testicles, ovaries, and the pelvis. Reported sites of metastatic spread include the liver, lungs, lymph nodes, brain, skull, and bones. It is characterized by the EWS-WT1 fusion protein.
Pleomorphic adenoma is a common benign salivary gland neoplasm characterised by neoplastic proliferation of epithelial (ductal) cells along with myoepithelial components, having a malignant potentiality. It is the most common type of salivary gland tumor and the most common tumor of the parotid gland. It derives its name from the architectural Pleomorphism seen by light microscopy. It is also known as "Mixed tumor, salivary gland type", which refers to its dual origin from epithelial and myoepithelial elements as opposed to its pleomorphic appearance.
Mucoepidermoid carcinoma (MEC) is the most common type of minor salivary gland malignancy in adults. Mucoepidermoid carcinoma can also be found in other organs, such as bronchi, lacrimal sac, and thyroid gland.
Acinic cell carcinoma is a malignant tumor representing 2% of all salivary tumors. 90% of the time found in the parotid gland, 10% intraorally on buccal mucosa or palate. The disease presents as a slow growing mass, associated with pain or tenderness in 50% of the cases. Often appears pseudoencapsulated.
Ewing sarcoma is a type of pediatric cancer that forms in bone or soft tissue. Symptoms may include swelling and pain at the site of the tumor, fever, and a bone fracture. The most common areas where it begins are the legs, pelvis, and chest wall. In about 25% of cases, the cancer has already spread to other parts of the body at the time of diagnosis. Complications may include a pleural effusion or paraplegia.
Salivary gland tumours, also known as mucous gland adenomas or neoplasms, are tumours that form in the tissues of salivary glands. The salivary glands are classified as major or minor. The major salivary glands consist of the parotid, submandibular, and sublingual glands. The minor salivary glands consist of 800 to 1000 small mucus-secreting glands located throughout the lining of the oral cavity. Patients with these types of tumours may be asymptomatic.
Clear cell sarcoma is a rare form of cancer called a sarcoma. It is known to occur mainly in the soft tissues and dermis. Rare forms were thought to occur in the gastrointestinal tract before they were discovered to be different and redesignated as gastrointestinal neuroectodermal tumors.
ETV6-NTRK3 gene fusion is the translocation of genetic material between the ETV6 gene located on the short arm of chromosome 12 at position p13.2 and the NTRK3 gene located on the long arm of chromosome 15 at position q25.3 to create the (12;15)(p13;q25) fusion gene, ETV6-NTRK3. This new gene consists of the 5' end of ETV6 fused to the 3' end of NTRK3. ETV6-NTRK3 therefore codes for a chimeric oncoprotein consisting of the helix-loop-helix (HLH) protein dimerization domain of the ETV6 protein fused to the tyrosine kinase domain of the NTRK3 protein. The ETV6 gene codes for the transcription factor protein, ETV6, which suppresses the expression of, and thereby regulates, various genes that in mice are required for normal hematopoiesis as well as the development and maintenance of the vascular network. NTRK3 codes for Tropomyosin receptor kinase C a NT-3 growth factor receptor cell surface protein that when bound to its growth factor ligand, neurotrophin-3, becomes an active tyrosine kinase that phosphorylates tyrosine residues on, and thereby stimulates, signaling proteins that promote the growth, survival, and proliferation of their parent cells. The tyrosine kinase of the ETV6-NTRK3 fusion protein is dysfunctional in that it is continuously active in phosphorylating tyrosine residues on, and thereby continuously stimulating, proteins that promote the growth, survival, and proliferation of their parent cells. In consequence, these cells take on malignant characteristics and are on the pathway of becoming cancerous. Indeed, the ETV6-NTRK3 fusion gene appears to be a critical driver of several types of cancers. It was originally identified in congenital fibrosarcoma and subsequently found in mammary secretory carcinoma, mammary analogue secretory carcinoma of salivary glands, salivary gland–type carcinoma of the thyroid, secretory carcinoma of the skin, congenital fibrosarcoma, congenital mesoblastic nephroma, rare cases of acute myelogenous leukemia, ALK-negative Inflammatory myofibroblastic tumour, cholangiocarcinoma, and radiation-induced papillary thyroid carcinoma.
Epithelial-myoepithelial carcinoma of the lung is a very rare histologic form of malignant epithelial neoplasm ("carcinoma") arising from lung tissue.
Endometrial stromal sarcoma is a malignant subtype of endometrial stromal tumor arising from the stroma of the endometrium rather than the glands. There are three grades for endometrial stromal tumors, as follows. It was previously known as endolymphatic stromal myosis because of diffuse infiltration of myometrial tissue or the invasion of lymphatic channels.
Sarcomatoid carcinoma of the lung is a term that encompasses five distinct histological subtypes of lung cancer, including (1) pleomorphic carcinoma, (2) spindle cell carcinoma, (3) giant cell carcinoma, (4) carcinosarcoma, or (5) pulmonary blastoma.
Salivary gland–like carcinomas of the lung generally refers a class of rare cancers that arise from the uncontrolled cell division (mitosis) of mutated cancer stem cells in lung tissue. They take their name partly from the appearance of their abnormal cells, whose structure and features closely resemble those of cancers that form in the major salivary glands of the head and neck. Carcinoma is a term for malignant neoplasms derived from cells of epithelial lineage, and/or that exhibit cytological or tissue architectural features characteristically found in epithelial cells.
Salivary duct carcinoma (SDC) is a rare type of aggressive cancer that arises from the salivary glands. It is predominantly seen in men and, generally, has a poor prognosis. Other high grade carcinomas can mimic SDC. About 40-60% of SDC arise in pleomorphic adenomas. Most, if not all, SDCs express androgen receptor by immunohistochemistry. Therapeutically relevant genetic alterations include ERBB2/Her2 amplification, PIK3CA and/or HRAS mutations.
Myoepithelioma of the head and neck, also myoepithelioma, is a salivary gland tumour of the head and neck that is usually benign. When malignant, which is exceedingly rare, they are known as malignant myoepithelioma or Myoepithelial carcinoma, and they account for 1% of the salivary tumors with poor prognosis.
Epithelial-myoepithelial carcinoma (EMCa) is a rare malignant tumour that typically arises in a salivary gland and consists of both an epithelial and myoepithelial component. They are predominantly found in the parotid gland and represent approximately 1% of salivary gland tumours.
Angiomatoid fibrous histiocytoma(AFH) is a rare soft tissue cancer that affects children and young adults. On November 16, 2020, US MasterChef Junior participant Ben Watkins died from the disease at the age of 14.
Mammary analogue secretory carcinoma (MASC), also termed MASCSG, is a salivary gland neoplasm. It is a secretory carcinoma which shares the microscopic pathologic features with other types of secretory carcinomas including mammary secretory carcinoma, secretory carcinoma of the skin, and salivary gland–type carcinoma of the thyroid. MASCSG was first described by Skálová et al. in 2010. The authors of this report found a chromosome translocation in certain salivary gland tumors, i.e. a (12;15)(p13;q25) fusion gene mutation. The other secretory carcinoma types carry this fusion gene.
Mammary secretory carcinoma (MSC), also termed secretory carcinoma of the breast, is a rare form of the breast cancers. MSC usually affects women but in a significant percentage of cases also occurs in men and children. Indeed, McDvitt and Stewart first described MSC in 1966 and termed it juvenile breast carcinoma because an increased number of cases were at that time diagnosed in juvenile females. MSC is the most common form of breast cancer in children, representing 80% of childhood breast cancers, although it accounts for less than 0.15% of all breast cancers.
The FET protein family consists of three similarly structured and functioning proteins. They and the genes in the FET gene family which encode them are: 1) the EWSR1 protein encoded by the EWSR1 gene located at band 12.2 of the long arm of chromosome 22; 2) the FUS protein encoded by the FUS gene located at band 16 on the short arm of chromosome 16; and 3) the TAF15 protein encoded by the TAF15 gene located at band 12 on the long arm of chromosome 7 The FET in this protein family's name derives from the first letters of FUS, EWSR1, and TAF15.