Name l Define l Risk l Detect l Treatment l Stage/Grade l Followup l Mets/Recur l Link
Names - Synonyms
This cancer, commonly found in the salivary glands and pancreas may also be referred to using the names - acinar cell carcinoma, acinic cell tumor, acinic cell adenocarcinoma, acinar cell adenocarcinoma, acinose carcinoma, and acinous carincoma.
Acinic Cell Carcinoma is a slow-growing malignant tumor, normally developing in the parotid glands and the major and minor salivary glands, upper lip, buccal mucosa, and the palate; and more rarely, in the parapharyngeal space, sublingual gland, pancreas, bones, breast, and lungs. In the pancreas, these tumors tend to be large (mean size ~10 cm), locally invasive, and usually metastatic (especially to liver) at the time of diagnosis.
Histologically, ACCs can resemble islet cell tumors, but they differ in their ultrastructural and immunohistochemical features. They have neoplastic cells that express acinar differentiation. By conventional use, the term acinic cell carcinoma is defined by cytologic differentiation towards serous acinar cells (as opposed to mucous acinar cells), whose characteristic feature is cytoplasmic PAS-positive zymogen-type secretory granules.
Risk Factors - Causes
Possible causes of ACC include previous radiation exposure, a familial predisposition, and wood dust inhalation. Women are more apt to get this cancer than men, except in the case of exocrine tumors of the pancreas. Middle aged people are also more apt to get this rare cancer. Although very rare, some children have also been diagnosed with this cancer.
ACC salivary patients typically present with a slowly enlarging mass in the parotid region. Pain, including flank pain, is a symptom in over a third of patients. Gastrointestinal symptoms may include nausea and vomiting, gradual weight loss, loss of appetite, digestion difficulties, a feeling of fullness, bloating, flatulence, alterations in bowel habits, fatty stool, and GI bleeding. Jaundice, chills and fevers, anorexia, cachexia, pruritis of the skin, swolling in the legs, pancreatitis, and abrupt onset of diabetes mellitus may also occur.
Pancreatic ACC patients may have joint pain and an increased level of eosinophils. Upon further evalulation, increased serum lipase, lobular panniculitis (mimicing erythema nodosum), and polyarthritis may also be found. If a CT scan is done, these tumors will show areas that are hypodense with occasional calcifications, a central necrotic area, and a well-defined, enhancing wall.
For salivary gland ACCs' the treatment of choice is surgical removal of the tumor, or the tumor and the gland involved. If facial nerves are involved, they may also be surgically removed. Radiation therapy may also be used as an adjunct therapy or .if there is suspected residual disease (positive margins), large primary tumors, lymph node involvement, perineural invasion, high grade histology, or other late stage conditions. Neutron beam radiation has been used successfully for this cancer.
For pancreatic ACC, the treatment choice depends on the stage of the cancer. Surgical resection is the best treatment in absence of distant metastasis. The extent of resection depends on the extent of the disease. En bloc resection has been reported in patients with locally advanced disease. Adjuvant chemotherapy and radiotherapy may help to prolong survival. 5-Fluorouracil is the commonest chemotherapeutic agent used.
Stage - Grade
Staging is usually more indicative of prognosis and follows the standard American Joint Committee on Cancer TNM staging system.
Poor prognostic features include pain or fixation; gross invasion; perineural invasion; and microscopic features of desmoplasia, atypia, or increased mitotic activity.
Because of the rarity of this cancer and lack of large scale studies, it should be consistently followed for the life of the patient.
Metastasis - Recurrence
There is considerable likelihood of recurrence (approx. 30-50%). Metastases occurs in approximately 20% of cases. These events may happen several years from original diagnosis.
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