What is adenoid cystic carcinoma of the lung?
Adenoid cystic carcinoma of the lung (ACCL) is a rare salivary gland-type malignant neoplasm that occurs infrequently as a primary tumor of the airway. Owing to its low incidence, the clinicopathological features, immunohistochemical expression spectrum, treatment and long-term survival have not been fully elucidated.
What is the cause of adenoid cystic carcinoma?
The exact cause of adenoid cystic carcinoma is unknown. However, current research suggests that genetic changes (mutations) are the underlying basis of cellular malignant transformation in many cancers, including ACC.
What is the significance of perineural invasion in adenoid cystic carcinoma?
There are three main ways by which tumors spread: direct invasion into adjacent tissues, hematogenous metastasis, and lymphatic spread; however, perineural invasion (PNI) is considered a fourth route of dissemination, which can be of great significance in the invasion and metastasis of tumors.
What is adenoid cystic carcinoma prognosis?
The overall five-year survival rate for all people with adenoid cystic carcinoma is 89%. This means that 89% of people who are diagnosed with the condition are still alive five years later. The estimated 10-year survival rate is less than 70%.
What is the meaning of perineural invasion?
Perineural invasion (PNI) is the process of neoplastic invasion of nerves and is an under-recognized route of metastatic spread. It is emerging as an important pathologic feature of many malignancies, including those of the pancreas, colon and rectum, prostate, head and neck, biliary tract, and stomach.
What does perineural invasion present mean?
Perineural invasion means that cancer cells were seen surrounding or tracking along a nerve fiber within the prostate. When this is found on a biopsy, it means that there is a higher chance that the cancer has spread outside the prostate.
Where is the perineural nerve located?
The perineural space is a compartment located between the nerve axons, supporting cells and tissues, and the epineural fibrous sheath. Tumor cells invade this space in response to a complex interplay of trophic factors in the local microenviroment.
Where is the perineural nerve?
The perineural space is a potential space beneath or between layers of perineurium, the middle layer of the peripheral nerve sheath.
Which tumor has perineural invasion?
Perineural invasion (PNI) is a common pathologic finding in many head and neck cancers, including squamous cell carcinoma (SCC) and adenoid cystic carcinoma (ACC; Table 1).
What is perineural carcinoma?
Perineural invasion (PNI) can be found in a variety of malignant tumors. It is a sign of tumor metastasis and invasion and portends the poor prognosis of patients. The pathological description and clinical significance of PNI are clearly understood, but exploration of the underlying molecular mechanism is ongoing.
What are the symptoms of perineural invasion?
When present, the signs and symptoms most commonly associated with perineural spread are pain, paresthesia including formication (ie, the sensation of ants or worms under the skin), numbness, and motor weakness (Table 1).
What is the meaning of perineural?
Around a nerve
(payr-ih-NOOR-ul) Around a nerve or group of nerves.
What is LVI and PNI?
Lymphovascular invasion (LVI) refers to the involvement of small lymphatic or blood (typically venous) vessels by tumor . Perineural invasion (PNI) refers to the growth of tumor in, around, and through nerves and nerve sheaths , .
What is perineural tumor spread?
Perineural tumor spread refers to the migration of tumor cells along nerve tissues. It worsens the prognosis, increases the recurrence rate, and diminishes 5-year survival by up to 30%.