Histopathologic grading of salivary gland neoplasms: II. Acinic cell carcinomas

Primary extra-pancreatic pancreatic-type acinar cell carcinoma in the right perinephric space: A case report and review of literature

BACKGROUND

Primary extra-pancreatic pancreatic-type acinar cell carcinoma (ACC) is a rare malignancy, and has only been reported in the gastrointestinal tract, liver, and lymph nodes until now. Extra-pancreatic pancreatic-type ACC in the perinephric space has not been reported. Herein, we report the first case of ACC in the perinephric space and describe its clinical and imaging features, which should be considered when differentiating perinephric space neoplasms.

CASE SUMMARY

A 48-year-old man with a 5-year history of hypertension was incidentally found to have an asymptomatic right retroperitoneal mass during a routine health check-up. Laboratory tests were normal. Abdominal computed tomography and magnetic resonance imaging showed an oval hypervascular mass with a central scar and enhanced capsule in the right perinephric space. After surgical resection of the neoplasm, the diagnosis was primary extra-pancreatic pancreatic-type ACC. The patient was alive without recurrence or metastasis during a 15-mo follow-up.

CONCLUSION

This is the first report of an extra-pancreatic ACC in right perinephric space, which should be considered as a possible diagnosis in perinephric tumors.

Perithyroidal Salivary Gland Acinic Cell Carcinoma: Morphological and Molecular Attributes of a Unique Lesion

Rarely, salivary gland tumors such as mucoepidermoid carcinoma, mammary analogue secretory carcinoma and mucinous carcinoma arise as primary tumors from ectopic or metaplastic salivary gland tissue adjacent to or within the thyroid gland. We report for the first time a case of primary salivary acinic cell carcinoma (AcCC) adjacent to the thyroid gland in a 71-year-old female patient with Crohns disease and a previous history of malignant melanoma. Following the development of a nodule adjacent to the left thyroid lobe, a fine-needle aspiration biopsy was reported as consistent with a follicular lesion of undetermined significance (Bethesda III). A left-sided hemithyroidectomy was performed. A circumscribed lesion measuring 33 mm was noted adjacent to the thyroid and trapping parathyroid, it was composed of solid nests and glands with microcystic and follicular patterns. The tumor was negative for thyroid, parathyroid and paraganglioma markers, but positive for pan-cytokeratins, CK7, CD10, CD117, androgen receptor and HNF-beta. A metastasis of a thyroid-like renal cell carcinoma was suspected but ruled out, and the patient had no evident lesions on extensive radiology of the urogenital, pulmonary and GI tracts. Based on the morphology, a diagnosis of AcCC was suggested, and confirmed with DOG1 and PAS-diastase staining. Molecular analyses pinpointed a constitutional ASXL1 variant of uncertain significance, but no fusion events. The patient had no radiological or clinical evidence of parotid, submandibular or sublingual tumors postoperatively, and the excised lesion was therefore assumed to be a primary tumor. We here detail the morphological and immunophenotypic profile of this previously undescribed perithyroidal tumor.

Intermediate-grade carcinoma of the parotid and the impact of adjuvant radiation

PURPOSE

To determine the influence of adjuvant radiotherapy on survival in surgically-managed early stage intermediate-grade mucoepidermoid and acinic cell carcinoma of the parotid.

MATERIALS AND METHODS

The National Cancer Database was reviewed between 2004 and 2015 to identify patients with intermediate-grade, early T-stage, node-negative parotid carcinoma who underwent parotidectomy ± radiotherapy.

RESULTS

There were 744 patients identified of which 81% had mucoepidermoid carcinoma and 19% had acinic cell carcinoma. Positive surgical margins were identified in 21% and adjuvant radiotherapy was administered in 38% of cases. Of the 159 patients with positive margins, 113 (71%) received adjuvant radiotherapy. Of the 585 patients with negative margins, 173 (30%) underwent adjuvant radiotherapy. In multivariable analysis, age (over 52 years: HR 5.19, 95%CI 2.33-11.57), insurance status (private insurance: HR 0.24 95%CI 0.13-0.43), and extent of parotidectomy (total parotidectomy: HR 2.02 95%CI 1.23-3.31) were significantly associated with overall survival, while adjuvant radiotherapy was not a significant predictive factor (HR 0.81, 95%CI 0.49-1.36). In patients with positive margin resections, however, adjuvant radiation was an independent predictor of improved survival when adjusted for age, insurance status, and extent of parotidectomy (HR 0.34, 95%CI 0.13-0.88). Conversely, in patients with negative margin resections, adjuvant radiation did not influence survival outcomes when adjusted for these covariates (HR 1.02, 95%CI 0.53-1.93).

CONCLUSIONS AND RELEVANCE

In patients with early stage intermediate-grade parotid carcinoma, adjuvant radiotherapy significantly and independently improves survival in those with post-operative positive margins. Adjuvant therapy, however, does not appear to improve survival outcomes in those with negative margin resections.

Four-Year Survival of a Patient With Spinal Metastatic Acinic Cell Carcinoma After a Total En Bloc Spondylectomy and Reconstruction With a Frozen Tumor-Bearing Bone Graft

Acinic cell carcinoma metastasizing to the spine is extremely rare. The authors present a case of acinic cell carcinoma of the parotid gland with subsequent lung and spinal metastases, treated with en bloc spondylectomy. A 41-year-old man presented with a left parotid mass. After being diagnosed with acinic cell carcinoma, he underwent a total parotidectomy. Imaging studies revealed a metastatic osteoblastic lesion in the T4 vertebral body and multiple lung metastases. Total en bloc spondylectomy and reconstruction with a frozen tumor-bearing bone graft were performed to treat the T4 metastasis. Lung metastases were treated with periodic radiofrequency ablation. At the 48-month follow-up, there was no local recurrence of the lesions, and the lung metastases were controlled. The bone graft had fused with the adjacent vertebrae, and the patient had full neurological function and normal daily activities. This report indicates satisfactory long-term outcomes of total en bloc spondylectomy and reconstruction with frozen tumor-bearing bone graft in a patient with acinic cell carcinoma with spinal metastasis. It also emphasizes the benefits of radical resection of spinal metastasis even in cases with multiple organ metastases. [Orthopedics. 2018; 41(5):e727-e730.].

Acinic Cell Carcinoma of the Parotid Gland in Children and Adolescents

Acinic cell carcinoma of the parotid gland is a rare low-grade malignant neoplasm. Data on children are sparse. For the present study, the database of a tertiary pediatric medical center was reviewed for all patients with parotid gland acinic cell carcinoma diagnosed and treated between 2004 and 2013. Clinical, histologic, treatment, and outcome parameters were collected from the medical files. Four patients were identified, 3 female and 1 male, aged 13.5 to 18 years (median 15.7) at diagnosis. One patient had a family history of parotid tumor and 1 of hypothyroidism/hyperthyroidism. Two patients had L-thyroxin-treated Hashimoto thyroiditis, and 1 had a thyroid nodule. All presented with a localized parotid mass and negative lymph nodes. Treatment consisted of partial parotidectomy, with no damage to the facial nerve. Histology confirmed the diagnosis of acinic cell carcinoma with low proliferation rate (Ki67 immunostaining 1% to 8%). No evidence of disease was found on any patient with a median follow-up at 83 months (range, 32 to 93 mo) from presentation. In our experience, the prognosis of pediatric parotid gland acinic cell carcinoma is good, and surgery alone is sufficient for treatment of early stage tumors. This is the first report of findings of a family history of thyroid disease and/or thyroid abnormalities in patients with parotid gland acinic cell carcinoma.

Report of a case of acinic cell carcinoma of the upper lip and review of Japanese cases of acinic cell carcinoma of the minor salivary glands

Acinic cell carcinoma (ACC) is a malignant tumor of the salivary glands. The majority of ACCs occur in the parotid gland, and ACCs of the minor salivary glands (MSGs) are relatively infrequent. We describe here a patient with ACC of the upper lip. The patient was a 31-year-old male who presented with a nodular mass on the left upper lip. The preoperative diagnosis was benign tumor or cyst, and the lesion was surgically excised. The histological diagnosis was ACC. The postoperative course was uneventful. No recurrence or metastasis was detected at 13 months postoperatively. In addition, we retrospectively reviewed 21 reported Japanese patients with ACC of the MSGs. In 7 of the 21 patients, the preoperative diagnosis was benign tumor, and the tumors were resected without preoperative biopsy. Kaplan–Meier analysis showed that disease-free survival was worse in patients who underwent resection with a preoperative diagnosis of benign tumor than in patients who underwent resection with a preoperative diagnosis of malignant tumor. The rate of recurrence was higher for ACCs assumed to be benign lesions on a purely clinical basis, or without an accurate preoperative biopsy. ACCs of the MSGs are easy to be misdiagnosed for benign lesions such as mucous cysts or hemangiomas. Correct preoperative diagnosis and initial therapy may therefore be the most important prognostic factors.

Key words:Acinic cell carcinoma, Kaplan-Meier analysis, minor salivary glands, prognosis, upper lip.

Salivary acinic cell carcinoma: reappraisal and update

Epidemiologic and clinicopathologic features, therapeutic strategies, and prognosis for acinic cell carcinoma of the major and minor salivary glands are critically reviewed. We explore histopathologic, histochemical, electron microscopic and immunohistochemical aspects and discuss histologic grading, histogenesis, animal models, and genetic events. In the context of possible diagnostic difficulties, the relationship to mammary analog secretory carcinoma is probed and a classification is suggested. Areas of controversy or uncertainty, which may benefit from further investigations, are also highlighted.

Solid blue dot tumour: minor salivary gland acinic cell carcinoma

Acinic cell adenocarcinoma (ACC) is a low-grade malignant salivary neoplasm that constitutes approximately 17% of all primary salivary gland malignancies. In the head and neck region, the parotid gland is the predominant site of origin and ACC is usually more frequent in women than men. Previous radiation exposure and familial predisposition are some of the risk factors for ACC. ACCs rarely involve minor salivary glands constituting only 13-17% of all minor salivary gland tumours. Generally, a slowly enlarging mass lesion in the tail of the parotid gland is the most frequent presentation. ACC has a significant tendency to recur, metastasise and may have an aggressive evolution. Therefore, a long-term follow-up is mandatory after treatment. Here we report the case of a woman in her 60s with an ACC in association with the labial minor salivary gland, presenting in the post-treatment period of squamous cell carcinoma of the tongue.

Prognostic factors associated with decreased survival in patients with acinic cell carcinoma

IMPORTANCE

Acinic cell carcinoma is a rare salivary neoplasm that is generally associated with a good prognosis, although a subset of patients develops local and distant recurrences. Given the rarity of the disease, factors to identify patients at risk for recurrences or decreased survival are not clearly defined.

OBJECTIVES

To identify clinicopathologic factors associated with adverse survival in patients with acinic cell carcinoma and to assess the effect of local, regional, and distant recurrences on survival.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective medical record review in a tertiary care cancer center of 155 patients treated for acinic cell carcinoma from January 1990 through February 2013.

MAIN OUTCOMES AND MEASURES

Primary outcomes evaluated were overall and disease-free survival. The end points assessed were age at diagnosis, sex, size of primary tumor, presence of positive surgical margins, postoperative radiation therapy, and development of local, regional, or distant recurrences.

RESULTS

The median survival was 28.5 years, with 13 patients (8.4%) dying of their disease. Women (n = 104) were affected twice as often as men (n = 51) but had an improved survival (P < .001). Patients diagnosed as having acinic cell carcinoma before or at the age of 45 years had an improved survival (P = .02) compared with their elder counterparts, a finding that was independent of sex. Neoplasms larger than 3 cm at presentation were associated with a decreased overall survival compared with smaller lesions (P = .02). The development of distant metastases was most associated with death from the disease (odds ratio, 49.90; 95% CI, 6.49-2246.30; P < .001) compared with local and regional recurrences.

CONCLUSIONS AND RELEVANCE

Although patients with acinic cell carcinoma generally have a favorable prognosis, we have identified several factors associated with decreased survival, including male sex, age older than 45 years, neoplasms larger than 3 cm, and the development of a distant recurrence. These results suggest that maximizing local and regional control for this disease can offer substantial benefit when no distant disease is detectable.

Skull base involvement by acinic cell carcinoma of the parotid gland

Objective Describe the clinical course and outcomes of patients with primary acinic cell carcinoma (ACC) of the parotid gland with skull base invasion or metastasis. Design Retrospective case series (1995-2011) at a single institution. Results Ten patients met study criteria. Mean and median time from initial diagnosis of parotid ACC to development of skull base disease were 14.6 and 10.2 years, respectively. Two patients demonstrated skull base disease on initial presentation. Those who pursued further treatment after developing disease at the skull base underwent surgery (4/7), stereotactic radiosurgery (4/7), or external beam radiation (3/7). The 10-year Kaplan-Meier estimated overall survival after initial diagnosis of parotid ACC was 80%. Once skull base invasion occurred, 2-year estimated overall survival was 50%. Conclusion Although primary ACC of the parotid generally caries an excellent prognosis, tumor control with cranial base disease is difficult and the majority of patients present with late aggressive recurrences. Our observations underscore the importance of long-term follow-up in this patient group.

Clinical analysis of acinic cell carcinoma in parotid gland

Objectives

Acinic cell carcinoma (AciCC) is a rarely encountered malignancy in parotid gland. Because AciCC is rare and was recently recognized as the entity of malignancy, AciCC has been difficult to study. We aimed to analyze the diagnosis and treatment experience for this malignancy in our hospital.

Methods

We retrospectively reviewed medical records of the 20 patients with AciCC of parotid gland diagnosed from 1990 to 2009. The preoperative computed tomography scan, preoperative fine needle aspiration cytology (FNAC) and intraoperative frozen section results were compared with the final diagnosis. The survival and recurrence were analyzed with the cancer stages and treatment modalities.

Results

There were 10 males and 10 females, with a mean age of 44.4 years, ranging 8-77 years. The AJCC tumor stage distributions of the patients were 70%, 15%, and 15% for stages I, II, and IV, respectively. The sensitivity of FNAC and intraoperative frozen section was 26.7% and 50.0% respectively. The 10-year survival rate was 90.9% with a mean follow-up of 111 months, ranging 17-251 months. The 10-year disease free survival rate was 74.2% and the mean duration of recurrence from initial surgery was 92.3 months.

Conclusion

AciCC of the parotid gland is a rare malignancy that has features of less aggressive behavior, and good prognosis. Intraoperative frozen section examination may be helpful in the diagnosis of AciCC of the parotid gland because of the low sensitivity of preoperative computed tomography scan and FNAC. Surgery with adjuvant postoperative radiotherapy is satisfactory for disease control.

Common Malignant Salivary Gland Epithelial Tumors

Malignant salivary gland epithelial tumors are histologically diverse with at least 24 recognized distinct entities. In general, malignant tumors account for 15% to 30% of parotid tumors, 40% to 45% of submandibular tumors, 70% to 90% of sublingual tumors, and 50% of minor salivary tumors. Common malignancies include mucoepidermoid carcinoma, adenoid cystic carcinoma, acinic cell carcinoma, salivary duct carcinoma, carcinoma ex pleomorphic adenoma, polymorphous lowgrade adenocarcinoma, and myoepithelial carcinoma. Each tumor type has its own unique histologic variants and prognostic pathologic features, and only mucoepidermoid carcinomas have a formalized grading system. The molecular pathogenesis of certain tumors, such as mucoepidermoid carcinoma and adenoid cystic carcinoma, has recently begun to be elucidated.

Current concepts on dedifferentiation/high-grade transformation in salivary gland tumors

The concept of dedifferentiation had previously been used in salivary gland carcinomas. Recently, the term “high-grade transformation” was introduced for adenoid cystic carcinoma, acinic cell carcinoma, epithelial-myoepithelial carcinoma, and polymorphous low-grade adenocarcinoma and may better reflect this phenomenon, although transformation into moderately differentiated adenocarcinoma (i.e., not “high grade”) has also been described. Among the immunohistochemical markers, Ki-67 seems to be the only one that can help distinguish between the conventional and transformed components; however, the combination of morphological criteria is still sovereign. The overexpression of p53 was observed in the transformed component in all tumor types studied, despite few cases having been demonstrated to carry mutations or deletions in TP53 gene. Genetic studies in salivary gland tumors with dedifferentiation/high-grade transformation are rare and deserve further investigation. This paper aims at providing an overview on the recent concepts in histopathological classification of salivary gland tumors, complemented by immunohistochemical and genetic findings.

Type II First Branchial Cleft Cyst: A Case Report with Review of Literature

We report a rare case of type II first branchial cleft cyst that presented as an intraparotid cyst. Rarity and varied presentations of the first branchial cleft cysts have led to frequent misdiagnosis. High index of suspicion is required. Complete excision is the main treatment.

Acinic cell carcinoma in pregnancy: a case report and review of the literature

Introduction

We report an observational study on the etiology and recurrence of acinic cell carcinoma of the parotid gland that seemed to be related to pregnancy. The medical literature has never reported such an association; therefore, our case report is probably the first to mention this observation.

Case presentation

This report is of a 25-year-old Arabic female patient from the United Arab Emirates, who, during her first pregnancy, developed acinic cell carcinoma of the right parotid gland that was managed with surgical excision in the form of superficial parotidectomy. During her second pregnancy, which occurred four years later, she had a recurrence of the same malignant neoplasm associated with ipsilateral malignant cervical lymphadenopathy. The patient was managed with total parotidectomy and neck dissection, as well as postoperative adjuvant radiotherapy. Our observation on this particular case of acinic cell carcinoma is that the initial onset of her neoplasm was during her first pregnancy, and the recurrence of the same malignant disease was during a subsequent pregnancy. This chronologic association raised our suspicion that there might be a possible etiologic effect of pregnancy or its associated hormonal or physiologic changes or both on the pathogenesis or etiology of acinic cell carcinoma.

Conclusion

Some association might exist between pregnancy and the pathogenesis or etiology of acinic cell carcinoma.

Prognostic factors in patients with high-risk locally advanced salivary gland cancers treated with surgery and postoperative radiotherapy

BACKGROUND

This study was designed to identify the factors associated with the outcome after standard treatment with surgery and postoperative radiotherapy (RT) for locally advanced salivary gland cancers.

METHODS

We conducted a retrospective review of patients with salivary gland cancers registered in the University of Pittsburgh databases from 1990 to 2006.

RESULTS

A total of 74 patients were analyzed. Histologic types included salivary duct carcinoma, 24%; adenoid cystic carcinoma, 23%; and adenocarcinoma, 19%; N2, 39%; N0-1, 58%; and major salivary gland origin, 80%. With a median follow-up of 4.1 years, the 5-year recurrence-free survival (RFS) was 49%, and the 5-year overall survival (OS) was 55%. The 5-year local RFS was 76% and the 5-year distant RFS was 60%. Using Cox-regression analysis, advanced N classification (N2) was the only significant predictor of both RFS and OS.

CONCLUSION

The long-term survival of patients with high-risk, locally advanced salivary gland cancers is unsatisfactory. Advanced nodal disease is strongly associated with patient outcome and should be considered as a stratification factor in future trials in locally advanced salivary gland cancers.

Mammalian target of rapamycin-dependent acinar cell neoplasia after inactivation of Apc and Pten in the mouse salivary gland: implications for human acinic cell carcinoma

Cross-talk between the canonical Wnt and mammalian target of rapamycin (mTOR) signaling pathways occurs at multiple levels in the cell and likely contributes to the oncogenic effects of these pathways in human cancer. To gain more insight into the interplay between Wnt and mTOR signaling in salivary gland tumorigenesis, we developed a mouse model in which both pathways are constitutively activated by the conditional inactivation of the Apc and Pten tumor suppressor genes. Loss of either Apc or Pten alone did not cause tumor development. However, deletion of both genes resulted in the formation of salivary gland tumors with 100% penetrance and short latency that showed a remarkable morphologic similarity to human acinic cell carcinoma. Treatment of tumor-bearing mice using the mTOR inhibitor rapamycin led to complete regression of tumors, indicating that tumor growth was dependent on continued mTOR signaling. Importantly, we found that human salivary gland acinic cell carcinomas also express markers of activated mTOR signaling. Together, these results suggest that aberrant activation of mTOR signaling plays a pivotal role in acinar cell neoplasia of the salivary gland. Because rapamycin analogues are approved for treating other types of human malignancies, our findings suggest that rapamycin therapy should be evaluated for treating patients with salivary gland acinic cell carcinoma.

Acinic cell carcinoma of minor salivary glands: a clinical and immunohistochemical study

PURPOSE

Acinic cell carcinoma is a rare malignant tumor of salivary glands. The purpose of this study is to evaluate the clinical outcome of acinic cell carcinoma in a group of 11 patients, who were treated in our clinic, and to discuss the management as well as the immunohistochemical features and prognosis of this carcinoma.

MATERIALS AND METHODS

The study included 11 patients with acinic cell carcinoma of the minor salivary glands who were treated in our clinic. The patients were 7 women and 4 men. The patients' age ranged from 46 to 83 years. The distribution of the primary sites was buccal mucosa (4) maxilla/maxillary sinus, etc, (2), hard palate (1), junction of soft/hard palate (1), lower lip (1), labio marginal sulcus (1), and vestibular sulcus and mandible (1). All patients were treated with surgery. Adjuvant radiotherapy was used in 3 patients. Immunohistochemical assay of expression of Ki-67, p53, EGFR, and c-erbB-2/neu markers was performed on specimens of all tumors.

RESULTS

The mean follow-up range was 2 to 15 years. Of the 11 patients, 7 were alive (2, 3, 4, 5, and 15 years after the initial therapy). Two patients died of another cause free of the disease 9 and 10 years after the initial treatment, and 2 patients died of the disease (local recurrence, distant metastases 2 and 3 years later). Overexpression of immunohistochemical markers was evident for tumors with widespread metastases.

CONCLUSIONS

Acinic cell carcinoma is a rare malignant tumor of the salivary glands, characterized by an indolent clinical course with the potential for both local recurrence and distant metastases. The immunohistochemical analysis of proliferation markers provides additional prognostic information for this tumor.

Parotid carcinoma: Current diagnostic workup and treatment

In this review we present recent progress in diagnostic workup, prognostic evaluation, treatment options and resulting outcomes. Whenever possible, complete resection remains the mainstay of treatment. Sacrifice of facial nerve branches is reserved for the clinically or electromyographically dysfunctioning facial nerve. Clinical or radiological neck disease demands combined surgery and radiotherapy. Treatment of the N0 neck is indicated for advanced stage-high grade tumors but the question remains unanswered whether this should be surgical or radiotherapeutic elective treatment. Surgery alone will cure low stage, low grade tumors, that show no additional negative prognostic factors following adequate resection. In all other tumors postoperative radiotherapy will improve locoregional control. This approach results in good locoregional control, in a way that distant metastasis remains the typical presentation of treatment failure. In this setting, the results of systemic treatment today remain limited, but a huge effort in the molecular biology field has been done to introduce targeted therapy into this domain of head and neck cancer. Disease control remains variable within the patient population. This variation can increasingly be predicted by systems that incorporate the combined information of multivariately identified and quantified prognostic factors into an individualized prognosis for the parotid carcinoma patient.

Obligate basal cell component in salivary oncocytoma facilitates distinction from acinic cell carcinoma

The differential diagnosis between benign salivary oncocytoma (ONC) and low-grade malignant acinic cell carcinoma (ACC) can be difficult due to a significant histomorphological overlap of the structural and cytological presentation of both tumor types. To the best of our knowledge a comprehensive study comparing (immuno-)histological markers in cases of difficult differential diagnosis between ONC and ACC has not yet been performed. We investigated a panel of different immunohistochemical (CK5/6, CK14, CK7, CK18, p63 and Ki67) and histochemical (PAS, alpha-amylase) markers in 12 cases of ONC and 19 cases of ACC. The statistically significant stronger expression of CK7 in ONC and stronger expression of PAS and alpha-amylase in ACC in routine practice each is hampered by a pronounced overlap between both tumor groups. The obligate presence of an additional small basal cell component in all cases of ONC, demonstrable with p63 and CK5/6, enables a straightforward distinction from ACC, being constantly devoid of a basal cell component. Unexpectedly, CK14 is not a suitable marker for a reliable proof of these basal cells. The detection of this basal cell component in ONC in routine Hematoxylin-eosin stain is difficult and in some cases not possible; therefore, immunohistochemistry with p63 or CK5/6 is recommended for selected cases.

Acinic cell carcinoma of the parotid gland: Auckland experience and literature review

Acinic cell carcinoma is an uncommon malignancy of the salivary glands and as such it has been difficult to accurately delineate its natural history. The aim of this study is to assess the behaviour of acinic cell salivary cancer of the parotid gland presenting to a single head and neck surgical unit in Auckland. The study is a structured review of cases of acinic cell carcinoma of the parotid gland presenting from 2000 to 2006 to the Head and Neck Unit at Auckland Hospital, those identified from the pathology database and the Otobase head and neck database. Case records and pathology reports were reviewed. Fifteen patients were identified, 9 men and 6 women. The mean age was 67.2 years, with range 50-85 years. The mean follow up was 4.4 years and range 1.1-7 years. There was one case of local recurrence during study period and no deaths. Five of 15 patients received postoperative radiotherapy. Postoperative complications consisted of one wound haematoma and two cases of marginal mandibular weakness (one transient and one permanent). Current management strategies are obtaining appropriate rates of recurrence and postoperative complications within the Auckland population.

Imaging of salivary gland tumours

Imaging of salivary gland tumours is a major challenge for radiologists due to the great variety of differential diagnoses. This article gives a short overview on the anatomy of the salivary glands, the epidemiology of salivary gland tumours as well as the clinical presentation and the different imaging modalities including new magnetic resonance techniques such as diffusion-weighted magnetic resonance imaging, dynamic contrast-enhanced magnetic resonance imaging and magnetic resonance spectroscopy applied in the work-up of salivary gland masses. The imaging features of different tumour types and their differential diagnoses are also discussed. Finally, staging classification and treatment options are presented.

Acinic cell carcinoma of the parotid gland: a 15-year review limited to a single surgeon at a single institution

The course of acinic cell carcinoma of the parotid gland following surgical and nonsurgical interventions is variable. The objective of this study was to report our experience in treating this disease and to evaluate the factors that might be involved in the treatment of the tumor and the prognosis of the patient. To limit the contributory variables that are usually found in most studies, we included only those patients (n = 11) who had been treated by a single surgeon at a single institution from 1988 through 2003. Hospital and office records were evaluated for demographic information, signs and symptoms, treatment modalities, pathology, and outcomes. Additional follow-up data were obtained through telephone interviews. For the most part, treatment included either superficial parotidectomy or total parotidectomy with facial nerve preservation; 1 patient with coexisting adenocarcinoma underwent a more radical procedure, and 4 patients underwent adjuvant radiation therapy. The most prevalent morphologic pattern of these tumors was microcystic. Follow-up ranged from 1 year and 3 months to 10 years and 9 months (mean: 4 yr and 11 mo). During that time, we found no recurrences of acinic cell carcinoma and no evidence of metastatic disease. Therefore, we conclude that acinic cell carcinoma can be successfully treated with a superficial or total parotidectomy with sparing of the facial nerve. Radiation therapy may provide adjunctive benefit.

Intracranial extension of acinic cell carcinoma of the parotid gland

We report the case of a 47-year-old woman who experienced multiple recurrences of acinic cell carcinoma, lung metastasis, and intracranial extension of the tumor during a 32-year period. In this report, the clinical, microscopic, histochemical, and electron microscopy features of this acinic cell carcinoma are described, and a review of published information about this neoplasm is presented.

Sinonasal acinic cell carcinoma: a clinicopathologic study of four cases

BACKGROUND

Acinic cell carcinoma is a low-grade malignant epithelial salivary gland neoplasm with a predilection for the parotid gland. To date, only 11 cases of sinonasal acinic cell carcinomas have been reported in the English-language literature. We present the clinicopathologic features of four sinonasal acinic cell carcinomas.

METHODS

The demographic data and pathologic material of four patients with sinonasal acinic cell carcinoma identified from the files of the Department of Pathology at The University of Texas M. D. Anderson Cancer Center between 1984 and 2002 were reviewed.

RESULTS

The four patients were two men and two women, with an age range of 42 to 65 years (mean, 54 years). The patients were initially seen with unilateral nasal obstruction. Histologically, all tumors were composed of round to ovoid cells with clear and/or basophilic granular cytoplasm and round, hyperchromatic, small, eccentrically located nuclei. The growth pattern was lobular, solid, and follicular. Histochemically, periodic acid-Schiff diastase-resistant granules were demonstrated in all cases. All patients were treated surgically. In addition, one patient received postoperative radiation. All patients are alive and well, with follow-up from 4 to 17 years.

CONCLUSIONS

Sinonasal acinic cell carcinoma is a distinct low-grade carcinoma that can be distinguished from other neoplasms by light microscopy and histochemical staining methods. Pathologists and surgeons should be aware of the occurrence of this type of salivary gland neoplasm in the sinonasal tract.

Transglottic acinic cell carcinoma. Case report and literature review

Acinic cell carcinoma (ACC) is a rare tumor generally involving the parotid gland and infrequently the minor salivary glands with the potential for both local recurrence and metastatic spread when tracked for decades. The biological behavior of ACC cannot be predicted on the basis of histological features, and surgical stage is still the best predictor of clinical outcome. Only 5 cases of ACC of the larynx have been reported in the English literature. The authors present a case of a rare transglottic ACC in a 74-year-old woman. At admission, a submucosal mass involving the left arytenoid and adjacent aryepiglottic fold was noted. A CT scan of the head and neck region showed a mass of the left hemilarynx involving the paraglottic space and extending from the aryepiglottic fold to the sinus piriformis. Definitive histopathological examination showed an ACC with a large amount of clear cells. The patient was treated by radiotherapy alone (66 Gy in 7 weeks) with complete remission.

Acinic cell carcinoma of the head and neck: radiologic-pathologic correlation

OBJECTIVE

To describe and correlate the imaging and pathologic findings of acinic cell carcinoma (ACC) in the head and neck.

METHODS

We reviewed the radiologic findings of 12 patients with pathologically proven ACC in the head and neck. They were 6 males and 6 females (ages: 5-75 years, mean 36 years) who undergoing computed tomography (CT, n=9) and CT with magnetic resonance (MR) imaging (n=3).

RESULTS

The lesions in the superficial lobe of the parotid gland were solid (n=7), cystic (n=1), and cystic mass with mural nodule (n=1) on CT. A parapharyngeal lesion was cystic mass with mural nodule, and a submandibular and a palate tumor were cystic lesions on CT. All solid masses in the parotid gland (n=7) included focal low-attenuating portions on CT, which were microcyst, hemorrhage, or necrosis on pathologic examination. We could not find intratumoral calcifications or metastatic lymphadenopathy on imaging and histologic studies in all 12 cases. Internal hemorrhage on the MR images was seen in a parapharyngeal and a parotid lesion.

CONCLUSION

Although ACC appears to have nonspecific imaging findings, familiarity with some imaging features can be helpful for differential diagnosis of head and neck tumors.

Gene expression screening of salivary gland neoplasms: molecular markers of potential histogenetic and clinical significance

Salivary gland neoplasms comprise phenotypically and biologically diverse lesions of uncertain histogenesis. The molecular events associated with their development and clinicopathological heterogeneity remain unknown. To reveal these events, we performed microarray expression analysis using a nylon-filter membrane platform on 18 primary lesions representing the most common benign and malignant types. Our study identified a small set of genes that are differentially altered between normal salivary gland tissues and benign and malignant tumors. Of the 5000 genes arrayed, 136 genes were differentially expressed by normal tissue, benign tumors, and various malignant neoplasms. Hierarchical clustering analysis differentiated between adenoid cystic carcinomas (ACCs) and other malignant subtypes. Non-ACC specimens manifested overlapping patterns of gene expression within and between tumors. Most of the differentially expressed genes share functional similarities with members of the adhesion, proliferation, and signal transduction pathways. Our study identified: 1) a set of genes that differentiate normal tissue from tumor specimens, 2) genes that differentiate pleomorphic adenoma and ACCs from other malignant salivary gland neoplasms, and 3) different patterns of expression between ACCs arising from major and minor salivary gland sites. The differentially expressed genes provide new information on potential genetic events of biological significance in future studies of salivary gland tumorigenesis.

Differential diagnosis of salivary acinic cell carcinoma and adenocarcinoma (NOS). A comparison of (immuno-)histochemical markers

A correct histologic differential diagnosis between salivary acinic cell carcinoma (ACC) and adenocarcinoma not otherwise specified (AC-NOS) is highly relevant because of the strikingly different biologic behavior and related therapeutical strategies. The distinction between both tumor types can be difficult because of an enormous variation in histologic appearance, with either type showing partially overlapping morphologic features. Owing to a lack of approved markers, the expression of PAS-staining, alpha-Amylase, alpha-1 Anti-trypsin, cytokeratin (CK)-subtypes 7/18 and Ki-67 was evaluated in 16 cases of ACC and 16 cases of AC-NOS. CK 7 is identified as the most reliable marker with strong positivity in AC-NOS, and complete or preponderant negativity in ACC. The characteristic membranous staining pattern of CK 18 in ACC, in contrast to a diffuse cytoplasmic pattern in AC-NOS, proved to be an additional valuable criterion. PAS and alpha-Amylase are only of little value when ACC is diagnosed, as many cases are only faintly positive or completely negative. The proliferation index (Ki-67) proved to be significantly higher in AC-NOS; however, the diagnostic usefulness is limited by a relevant overlap. In conclusion, we recommend CK 7 and 18 as the most valuable markers in cases with difficult differential diagnosis between ACC and AC-NOS.

Dedifferentiated acinic cell carcinoma of the parotid gland with myoepithelial features

Dedifferentiated acinic cell carcinoma of the salivary gland is an uncommon variant of acinic cell carcinoma, characterized by the coexistence of both an usual low-grade acinic cell carcinoma and a high-grade dedifferentiated component, as well as by an accelerated clinical course. We describe a case of acinic cell carcinoma of the parotid gland in a 67-year-old woman, which recurred 4 times after surgery and radiotherapy. The recurrences consisted of residual foci of acinic cell carcinoma intermingled with a high-grade epithelial proliferation; the latter was focally constituted by cells with morphologic and immunohistochemical features of myoepithelium.

Acinic cell carcinoma of the lacrimal gland with intracranial extension: a case report

PURPOSE

To describe a patient with acinic cell carcinoma of the lacrimal gland presenting with atypical manifestations including erosion of the orbital roof and intracranial extension. We compare his clinical manifestations with two previously reported cases.

METHODS

Case report.

RESULTS

A 51-year-old man presented with a firm, tender, palpable mass in the superior temporal portion of his right orbit. CT scan demonstrated a large homogeneously enhancing mass displacing the globe inferiorly and eroding the roof of the orbit. MRI of the orbit showed intracranial extension of tumor. Biopsy revealed an acinic cell carcinoma of the lacrimal gland.

CONCLUSIONS

Acinic cell carcinoma is a rare neoplasm occurring primarily in the major and minor salivary glands.

Dedifferentiation occurring in adenoid cystic carcinoma of the tongue

A 61-year-old man came to the University of Granada School of Dentistry complaining of a mass involving his ventral tongue. Histopathologic examination of the excised specimen showed adenoid cystic carcinoma in which cribriform and tubular patterns were observed, juxtaposed with an undifferentiated carcinoma, large-cell type. No cervical lymph node metastasis was present, and the patient is alive and free of disease 5 years after treatment. To our knowledge, no similar cases have been reported thus far, though other salivary gland malignancies have been described in association with undifferentiated carcinoma, especially in the parotid gland. These neoplasms have been highly aggressive, and the adequacy of the primary surgical resection may be critical in determining the ultimate prognosis and survival.

National Cancer Data Base report on cancer of the head and neck: acinic cell carcinoma

BACKGROUND

Management of acinic cell carcinoma is based on reports of small numbers of cases accrued over several decades.

METHODS

The National Cancer Data Base (NCDB) identified 1353 cases of acinic cell carcinoma of the head and neck for the years 1985 to 1995. Chi square analyses of selected contingency tables and Wilcoxon regression analyses of selected survival stratifications are presented.

RESULTS

Five-year survival was 83.3% (observed) and 91.4% (disease specific). Worse survival was associated with high grade (p < .0001), age greater or equal to 30 years (p = .0055), and the presence of metastatic disease (p < .0001).

CONCLUSIONS

An aggressive subset of acinic cell carcinoma which is characterized by high grade and advanced stage rarely occurs in patients younger than 30 years old. Although better outcome was not statistically demonstrated for combined therapy, surgery with irradiation is the most common management in the United States for cases with regional metastases, high grade, and microscopic positive margins.

Genetic alterations in acinic cell carcinoma of the parotid gland determined by microsatellite analysis

We investigated, for the first time, the genetic alterations at certain chromosomal loci in 25 primary parotid acinic cell carcinomas to define the most frequently altered chromosomal regions and their association with pathologic features and DNA content analysis. Our results showed that 21 (84.0%) of the tumors had alteration in at least one of the loci tested. In general, chromosomal regions at chromosomes 4p, 5q, 6p, and 17p were more frequently altered than those on chromosomes 1p and 1q, 4q, 5p, and 6q. Certain markers at 4p15-16, 6p25-qter, and 17p11 regions showed the highest incidence of LOH, suggesting the presence of tumor suppressor genes associated with the oncogenesis of these tumors. LOH was significantly associated only with tumor grade. No apparent correlation between LOH and other clinicopathologic and DNA content characteristics was identified. Our study broadly defined the chromosomal arms and loci that may be targeted for further localization of the minimally deleted regions involved in the tumorigenesis of these tumors.

Clear cell neoplasms in salivary glands: clearly a diagnostic challenge

Although infrequent, salivary gland tumors with a dominant population of clear staining cells present problems in differential diagnosis. Mucoepidermoid carcinoma, acinic cell adenocarcinoma, "clear cell" oncocytoma, epithelial-myoepithelial carcinoma, clear cell adenocarcinoma, and metastatic renal cell carcinoma are considered in the differential diagnosis. This review focuses on this heterogenous group of clear cell neoplasms and attempts to clarify some of the features that help distinguish one neoplasm from another.

Well-differentiated acinic cell carcinoma of salivary glands associated with lymphoid stroma

In a multicenter study, 69 acinic cell carcinomas of the salivary glands were identified, of which 12 constituted what the authors believe to be a distinct subgroup. Their most noticeable feature was a dense lymphoid stroma with well-developed germinal centers, surrounding a sometimes scanty epithelial component, which in each case had a microcystic growth pattern. All these tumors were enveloped by a thin fibrous pseudocapsule, thus mimicking an intraparotid lymph node containing a metastasis. All 12 cases showed low MIB1 proliferative activity, with a mean index of 1.7% (range, 0.5 to 3.7). All patients remained well without recurrence or metastasis in followup periods of 19 months to 14 years. A second subgroup of nine acinic cell carcinomas also possessed a heavy lymphoid stroma with germinal centers, but its distribution was more patchy than in the first subgroup, and in addition, the fibrous pseudo-capsule was incomplete or absent. In each case the epithelial growth pattern was other than microcystic. These tumors had significantly higher MIB1 indices (mean, 17%; range, 3.4 to 45). In contrast to the first subgroup, only three of nine patients remained well with no further disease. The other six patients developed recurrences or metastases, and two died of disseminated cancer. In view of the clinical and pathological data, it is speculated that the tumor foci lacking lymphoid stroma in each of the second subgroup possibly represented a clone of high-grade malignancy arising within a low-grade acinic cell carcinoma with lymphoid stroma.