[Effectiveness of minimally invasive surgery in the treatment of pancreatic acinar cell carcinoma].

Objective: To explore the effectiveness of minimally invasive surgical treatment for pancreatic acinar cell carcinoma (PACC). Methods: Six patients with PACC diagnosed in Peking University Third Hospital from January 2010 to September 2022 were retrospectively selected. Preoperative evaluation was performed on whether the lesions were eligible for surgery, including whether radical resection of liver metastases could be performed. Laparoscopic or Da Vinci robot-assisted resection was performed on six patients, and spleen retention was determined according to the original lesions and the relationship with peripheral blood vessels and tissues, while simultaneous resection was performed on cases of peripheral organ tissue invasion. The patients' basic information, preoperative general conditions, preoperative diagnosis and tumor stage, minimally invasive surgery methods, postoperative complications, pathological results, tumor stage and follow-up data were collected and analyzed to explore the effectiveness of minimally invasive surgery. Results: Among the six patients, four were males and two were females, with the age of 25-69 years. Five patients had abdominal pain and distension before surgery, five patients had tumors located at the tail of the pancreatic body, and one patient had tumors located at the head of the pancreas. Preoperative imaging (enhanced CT and MRI) was performed to measure the tumor diameter (2.8-10.0 cm). Tumor markers were elevated in two patients before surgery, and six patients underwent surgery through laparoscopy or robotic platform. No complications such as postoperative pancreatic fistula and bleeding were clinically relevant during and after surgery. There were two cases with concurrent or heterochronous liver metastasis, two cases with lymph node metastasis and nodular metastasis, four cases with tumor invasion of surrounding organs (stomach, spleen or duodenum), and three cases with vascular cancer thrombi. The follow-up time of the six patients was 12 to 165 months, and one patient underwent three operations due to postoperative liver metastasis and residual pancreatic recurrence, and the results were satisfactory. All the six patients survived at the last follow-up. Conclusions: PACC is prone to invade the surrounding organs, and has a large tumor diameter. Radical surgery for PACC can be completed through minimally invasive surgery, and satisfactory oncology prognosis can be obtained. In addition, some PACC patients with recurrence and metastasis can still be treated by surgery.

Successful endotracheal intervention for primary tracheal acinic cell carcinoma: A case report and literature review.

INTRODUCTION: Primary tracheal acinic cell carcinoma (ACC) is an exceptionally rare malignancy, posing challenges in understanding its clinical behavior and optimal management. Surgical resection has traditionally been the primary treatment modality, but we present a compelling case of tracheal ACC managed with endotracheal intervention, challenging conventional approaches. PATIENT CONCERNS: A 53-year-old woman presented with shortness of breath, cough, and hemoptysis. Enhanced computed tomography revealed an obstructive tracheal lesion, leading to her referral for further assessment. DIAGNOSIS: Microscopic evaluation, immunohistochemistry, and clinical assessments confirmed primary tracheal ACC, an exceedingly rare condition with limited clinical insights. INTERVENTIONS: We utilized rigid bronchoscopy to perform endotracheal intervention, successfully resecting the tumor and restoring tracheal patency. Postoperatively, the patient received no radiotherapy or chemotherapy. OUTCOMES: The patient achieved complete recovery, with 24-month follow-up examinations indicating no recurrence or metastatic disease. Only minimal scar tissue remained at the resection site. CONCLUSION: This case demonstrates the potential of endotracheal intervention as a curative approach for primary tracheal ACC, minimizing invasiveness and preserving tracheal function. Collaborative research efforts and extensive case reporting are crucial for advancing our understanding of this rare malignancy and optimizing treatment strategies for improved patient outcomes.

Acinic cell carcinoma of the oral and maxillofacial region: an international multicenter study.

The aim of this study was to describe the prevalence, clinicopathological, and prognostic features of acinic cell carcinoma (AciCC) of the oral and maxillofacial region. AciCC cases were retrospectively retrieved from 11 pathology centers of three different countries. Medical records were examined to extract demographic, clinical, pathologic, and follow-up information. A total of 75 cases were included. Females (65.33%) with a mean age of 45.51 years were mostly affected. The lesions usually presented as an asymptomatic (64.28%) nodule (95.66%) in the parotid gland (70.68%). The association of two histopathological patterns was the most common finding (48.93%) and the tumors presented mainly conventional histopathological grades (86.11%). Surgical treatment was performed in the majority of the cases (59.19%). Local recurrence was observed in 20% of the informed cases, regional metastasis in 30.43%, and distant metastasis in 12.50%. The statistical analysis showed that the cases with a solid histopathological pattern (p=0.01), high-grade transformation (p=0.008), recurrence (p=0.007), and regional metastasis (p=0.03) were associated with poor survival. In conclusion, high histopathological transformation, presence of nodal metastasis, and recurrence were prognostic factors for AciCC of the oral and maxillofacial region.

Pancreatic Mixed Acinar-neuroendocrine-ductal Carcinoma: A Case Report and Literature Review.

Pancreatic mixed neoplasms are very rare. We herein report a unique case of pancreatic mixed acinar-neuroendocrine-ductal carcinoma with trilineage differentiation. The patient was an 83-year-old woman referred to our hospital due to anemia and a pancreatic mass. Contrast-enhanced computed tomography revealed a 60-mm mass in the pancreas. Subtotal stomach-preserving pancreaticoduodenectomy was performed. The postoperative pathological diagnosis was mixed acinar-neuroendocrine-ductal carcinoma. Postoperative chemotherapy was conducted according to the adenocarcinoma and neuroendocrine carcinoma protocols. The patient died 26 months postoperatively. Choosing appropriate chemotherapy for mixed neoplasms is difficult. Cancer gene panel testing, if possible, may support the choice of therapeutic agents.

Prognostic Assessment and Risk Stratification in Patients With Postoperative Major Salivary Acinar Cell Carcinoma.

OBJECTIVE: To investigate the clinicopathological features and prognosis of postoperative major salivary acinar cell carcinoma (MSACC) and develop a prognostic model. STUDY DESIGN: Retrospective cohort analysis of a public database. SETTING: Patients with MSACC were identified from the Surveillance, Epidemiology, and End Results database (1975-2019). METHODS: Overall survival (OS) was evaluated using Kaplan-Meier curves and a log-rank test. Univariate and multivariate Cox analyses were performed to explore independent prognostic factors. The prognostic model was constructed using screened variables and further visualized with a nomogram and web calculator, and assessed by concordance index, the area under the curve, calibration curve, and decision-making curve analysis. RESULTS: An upward trend in the incidence of MSACC was observed throughout the study period. A total of 1398 patients were enrolled (training cohort: 978; validation cohort: 420), and the 5- and 10-year OS rates were 97.7% and 81.6%, respectively. Age, marital status, sex, histological grade, T stage, and lymph node status were identified as prognostic factors for OS. A novel nomogram was developed and showed excellent discrimination and clinical applicability. Additionally, a web calculator was designed to dynamically predict patient survival. Based on the nomogram-based score, a risk stratification system was constructed to distinguish patients with different risks. The OS of high-risk patients was significantly lower than that of the low-risk subgroup. CONCLUSION: Long-term survival in postoperative MSACC was influenced by 6 prognostic factors. The proposed model enables individualized survival prediction and risk stratification, prompting us to be vigilant in high-risk subgroups and consider timely adjustment of subsequent treatment.

Survival outcomes, prognostic factors, and effect of adjuvant radiotherapy and prophylactic neck dissection in salivary acinic cell carcinoma: A prospective multicenter REFCOR study of 187 patients.

BACKGROUND: Acinic cell carcinomas (AciCCs) are malignant tumours of the salivary glands. The aim of this work was to analyse data from the national REFCOR multicenter cohort (i) to investigate the prognostic factors influencing survival outcomes in AciCC, (ii) to assess the impact on survival of postoperative radiotherapy (RT) in patients treated for AciCC without high-grade transformation and (iii) to explore the prognostic impact of prophylactic neck dissection (ND) in patients treated for AciCC of the major salivary glands. PATIENTS AND METHODS: Data from all the patients treated for salivary AciCC between 2009 and 2020 were extracted from the REFCOR database. Survival outcomes and prognostic factors influencing Disease-Free Survival (DFS) and Overall Survival (OS) were investigated using univariate and multivariate analyses. Propensity score matching was used to assess the impact of postoperative RT and prophylactic ND on DFS. RESULTS: A total of 187 patients were included. After a median follow-up of 53 months, their 5-year OS and DFS rates were 92.8% and 76.2%, respectively. In multivariate analysis, male sex, older age, higher T and N status, and high grade were independently associated with a worse DFS. In the subpopulation analysed after propensity score matching, patients with cN0 AciCC without high-grade transformation who were treated by surgery and RT did not have an improved DFS compared to patients who were treated by surgery alone (hazard ratio (HR) = 0.87, p = 0.8). Factors associated with nodal invasion were T3-T4 status and intermediate/high histological grade. After propensity score matching, prophylactic ND was associated with a trend toward a better DFS (HR = 0.46, p = 0.16). CONCLUSIONS: These results suggest that (i) long-term follow-up (>5 years) should be considered in patients with AciCC, (ii) treatment by surgery alone could be an option in selected cN0 patients with AciCC without high-grade transformation and (iii) prophylactic ND may be considered preferentially in patients with T3-T4 status and/or intermediate/high histological grade.

Primary acinic cell carcinoma of the trachea: A case report and literature review.

RATIONALE: Salivary gland-type acinic cell carcinoma (ACC) is a low-grade malignancy. Primary ACC of the trachea and lungs is rare; here, we describe 1 such case. The histological morphology of tracheal ACC was similar to that of its salivary gland-associated equivalent. Because of its rarity, it is easily misdiagnosed as another type of tracheal or lung tumor. Microscopic analysis of pathological features and immunohistochemistry help diagnose primary ACC of the trachea and lungs. PATIENT CONCERNS: A 33-year-old female complained of shortness of breath and hemoptysis for 2 years, and reported the symptoms to have aggravated over the last 4 months. The patient was admitted to our hospital for further treatment. Enhanced computed tomography revealed a soft tissue density nodule shadow in the trachea, which was approximately 1.3 × 1.2 cm in size. DIAGNOSES: Based on the clinical information, morphological features, and immunohistochemistry, the pathological diagnosis was primary ACC of the trachea. INTERVENTION: The tracheal lesion was resected with an electric snare, electrotomy, freezing, and an argon knife using a rigid bronchoscope. OUTCOMES: The patient's postoperative course was uneventful. LESSONS: It is important to prevent misdiagnosis of this type of tumor as another type of lung tumor. Morphological and immunohistochemical features can be useful in diagnosing primary ACC of the trachea and lungs.

Acinar cell carcinoma with PRKAR1A and PTEN alterations and paraneoplastic panniculitis.

Pancreatic acinar cell carcinoma is a rare type of pancreatic malignancy, which can be confused with pancreatic neuroendocrine neoplasm. Here, we describe a woman in her 80s who presented with abdominal pain and bilateral lower extremity panniculitis. She underwent surgery for a presumed diagnosis of neuroendocrine tumour with PTEN and PRKAR1A alterations; 19 months, later, a recurrence of her pancreatic malignancy was discovered. The patient underwent repeat resection and this time immunohistochemical staining confirmed the diagnosis of acinar cell carcinoma. Staining for acinar cell carcinoma should be prompted based on clinical suspicion in context of PTEN or PRKAR1A mutation when appropriate.

Painful lower limb nodules as first symptom of resectable pancreatic acinar cell cancer: a case report.

BACKGROUND: Pancreatic panniculitis is characterized by subcutaneous fat necrosis and is a rare presentation of an underlying pancreatic disease, appearing in approximately 2-3% of all patients with a pancreatic disease. The nodules usually involve the lower extremities. Pancreatic panniculitis is commonly associated with acute or chronic pancreatitis, and occasionally with pancreatic cancer, especially acinar cell carcinoma. CASE PRESENTATION: A 77-year-old Caucasian woman with no significant medical history was referred to our center with multiple painful, itchy, and warm red/blue cutaneous nodules on the left lower leg. These skin lesions were consistent with the clinical diagnosis of panniculitis. The skin biopsy obtained showed a predominantly lobular panniculitis with fat necrosis of which the aspect was highly suspicious for pancreatic panniculitis. Further analysis revealed high lipase serum of > 3000 U/L (normal range < 60 U/L), and on computed tomography scan a mass located between the stomach and the left pancreas was seen. Endoscopic ultrasonography-guided fine-needle biopsy confirmed the diagnosis of acinar cell carcinoma. After discussing the patient in the pancreatobiliary multidisciplinary team meeting, laparoscopic distal pancreatectomy including splenectomy and en bloc wedge resection of the stomach due to tumor in-growth was performed. The cutaneous nodules on both legs disappeared 1-2 days after surgery. No long-term complications were reported during follow-up. One year after surgery, the patient presented with similar symptoms as preoperatively. Computed tomography scan showed local recurrence and distal metastases, which were subsequently confirmed by biopsy. She started with palliative folinic acid-fluorouracil-irinotecan-oxaliplatin chemotherapy but stopped after two cycles because of disease progression. The patient died 2 months later, 13 months after surgical resection. CONCLUSION: This case illustrates the importance of clinically recognizing cutaneous nodules and pathological recognizing the specific microscopic changes as sign of a (malignant) pancreatic disease.

Successful conversion surgery after FOLFIRINOX therapy in a patient with advanced pancreatic acinar cell carcinoma with a solitary peritoneal dissemination: A case report.

BACKGROUND: Pancreatic acinar cell carcinoma is rare; it accounts for 1% of all malignant pancreatic exocrine tumors. Although surgical resection is an option for curative treatment, the safety and efficacy of conversion surgery in patients with pancreatic acinar cell carcinoma with metastasis remain unknown. CASE: A 67-year-old man with epigastric pain and a pancreatic tumor was referred to our hospital. Computed tomography revealed a large tumor with a maximum diameter of 67 mm at the pancreatic head and a 23-mm mass in the left upper abdominal cavity. Because a definitive diagnosis could not be made based on endoscopic ultrasonography-guided fine needle aspiration biopsy findings, a diagnostic laparoscopy was performed. The tumor in the greater omentum at the left upper abdomen, resected under laparoscopy, was histopathologically diagnosed as pancreatic acinar cell carcinoma. Therefore, the pancreatic tumor was diagnosed as an unresectable pancreatic acinar cell carcinoma with a solitary peritoneal dissemination. The size of the main pancreatic tumor decreased to 15 mm after 18 courses of FOLFIRINOX (5-fluorouracil, leucovorin, irinotecan, and oxaliplatin). Subsequently, the patient underwent conversion surgery, and the initial diagnosis of pancreatic acinar cell carcinoma was confirmed on pathological examination. The patient was discharged 31 days postoperatively, following which he received adjuvant chemotherapy with S-1. No sign of recurrence has been observed for 32 months after surgical resection. CONCLUSION: FOLFIRINOX may be effective in patients with pancreatic acinar cell carcinoma, and conversion surgery after FOLFIRINOX may be applicable to selective patients.

NR4A3 fluorescence in situ hybridization analysis in cytologic and surgical specimens of acinic cell carcinoma.

Acinic cell carcinoma (AciCC) may pose a diagnostic challenge, particularly on small biopsies and fine needle aspiration (FNA) because of its variable histology including potential high-grade transformation and its mimickers. Immunoreactivity with circumferential membranous staining for DOG1 can support the diagnosis of AciCC but is not entirely specific. A novel rearrangement t(4;9)(q13;q31) leading to up-regulation of nuclear receptor subfamily 4 group A member 3 (NR4A3) has been described in AciCC, is potentially detectable by fluorescence in situ hybridization (FISH) and may be useful in the evaluation for AciCC. Using NR4A3 Dual Color Break Apart Probe (ZytoVision, Germany) FISH was performed on AciCCs from 3 large academic institutions. NR4A3 rearrangement was defined as positive signal patterns in 15% of tissue interphase nuclei. Fifty-two AciCCs including 47 resections and 5 FNAs (including 5 paired FNA/resections) were analyzed. Five non-AciCC salivary gland tumors and 2 sialadenitis cases were used as controls. Eight AciCCs (15%; 8/52) failed FISH testing. FISH was positive in 23 AciCCs (sensitivity 59%, 23/39) with 100% concordance between 5 matched resection/FNAs (3 were positive for FISH and 2 were negative). FISH was negative in all non-AciCCs (specificity: 100%, 0/7). NR4A3 FISH has a sensitivity of 59% and specificity of 100% in detecting AciCC, which suggests that NR4A3 rearrangement-driven up-regulation is a recurrent, specific oncogenic event in AciCC, consistent with prior results. Hundred percent concordance between matched FNA/resection samples validates its potential utility on cytology samples.

Prognostic factors in acinic cell carcinoma of the head and neck: The Amsterdam experience.

INTRODUCTION: The aim was to analyse prognosticators in acinic cell carcinoma (AciCC) in two head and neck referral centers in Amsterdam, the Netherlands. MATERIALS AND METHODS: Eighty- nine cases of AciCC treated between 1979 and 2016 were retrospectively reviewed. Five, - 10 -and 20- year estimates of survival were executed as well as univariate analysis of prognosticators. RESULTS: The majority of AciCC were T1-T2; 89%. Two percent had nodal disease (2%). The most affected organ was the parotid gland (84%) with a female preponderance (67%). Mean age was 52 years with most cases diagnosed in the fourth to sixth decade. The majority of patients received adjuvant radiotherapy. Elective neck dissection (END) in the N0 neck showed no metastases. High grade transformation (HGT) was found in 21% of cases. Median follow up was 101.9 months. Median time to recurrence was 26 months. Nine patients developed distant metastases (DM) of whom 6 had HGT-AciCC. Median survival with DM was 7 months. Five,- ten -and twenty- year estimates were 84%, 81% and 81% for recurrence free survival respectively. Negative clinical features were advanced stage disease and tumour size > 2.6 cm. Negative histological features were a high mitotic rate, HGT, close and involved surgical margins and necrosis. CONCLUSION: AciCC- HGT excluded- of the head and neck has an excellent prognosis and shows acceptable long term results. END can be considered as part of the standard treatment due to the relative high incidence of HGT- AciCC and low accuracy of cytology.

Defining the role of systemic therapy in resectable pancreatic acinar cell carcinoma.

INTRODUCTION: Following resection of pancreatic acinar cell carcinoma (PACC) distant recurrence remains high. We utilized the national cancer database (NCDB) to evaluate the role of systemic therapy in early-stage resected PACC. METHODS: We queried the NCDB registry from 2004 to 2015 for patients with pathologic stage I-IIB PACC. For each stage, patients who underwent surgery alone (SA) were compared to patients who received systemic and/or radiation therapy in addition to surgery (surgery + therapy [S + T]). RESULTS: A total of 271 patients (101 pI, 81 pIIA, and 89 pIIB) were analyzed. Of all clinically node positive patients (n = 41), the majority (n = 32, 78%) had node-positive disease at resection (pIIB). SA was performed in 112 patients (41.3%), whereas 159 (58.7%) patients received S + T. There was no difference in overall survival (OS) between S + T and SA with respect to pI or pIIA disease. In pIIB disease, S + T was associated with improved OS compared to SA (34.9 vs. 16.9 months, p = 0.031). Single-agent chemotherapy was associated with improved OS for pIIB disease when compared to SA (hazard ratio: 0.38, 95% confidence interval: 0.16, 0.83). CONCLUSION: In resectable PACC, the survival benefit of adjuvant therapy is limited to pathologic stage IIB disease. This benefit is evident even in patients treated with single-agent chemotherapy.

A case of pathologically complete response after preoperative chemotherapy in a pancreatic acinar cell carcinoma patient with portal vein tumor thrombosis.

Preoperative treatment is being proposed as a standard treatment for pancreatic ductal adenocarcinoma though few cases show a pathologically complete response. On the other hand, there is no consensus regarding preoperative chemotherapy for pancreatic acinar cell carcinoma (ACC). The present study described a rare case of ACC in the pancreatic head with portal vein tumor thrombosis (PVTT) treated with preoperative chemotherapy using modified FOLFIRINOX, which achieved a pathologically complete response. A 65-year-old man was referred for consideration of treatment strategy. Contrast-enhanced abdominal computed tomography revealed a pancreatic tumor and PVTT. The pancreatic tumor was diagnosed as ACC by an endoscopic ultrasound-guided fine-needle aspiration biopsy. Initially, the tumor was assessed as unresectable due to the presence of PVTT, and therefore, a chemotherapy using modified FOLFIRINOX was administered. After 14 courses of the chemotherapy, imaging studies revealed that the tumor and PVTT showed marked reduction in size; thus, the patient underwent pancreaticoduodenectomy with combined resection of the portal vein (PV). A pathological examination uncovered a complete degeneration of the primary tumor and the PV embolus without any residue of carcinoma. The patient did not receive adjuvant chemotherapy and survived with no evidence of recurrence for 33 months after surgery. The chemotherapy using modified FOLFIRINOX could give a complete response in patients with pancreatic ACC with PVTT.

Primary salivary acinar cell carcinoma of the parotid gland with parietal skull metastasis: A case report.

Acinar cell carcinoma of the salivary gland (AciCC) is a rare low-grade epithelial malignant tumor of the salivary gland. The primary site of the disease is often in the parotid gland, followed by the submandibular gland and small salivary gland. In the early stage of the disease, there are no obvious symptoms, most of which are slow enlargement of the mass, accompanied by local pain or discomfort, or facial paralysis involving the facial nerve. Although the disease is a low-grade malignant tumor, it is invasive to a certain extent and prone to recurrence and metastasis. The metastasis sites are usually liver, lung, stomach and other visceral organs, while the metastasis of brain and skull is rarely reported by other authors. This paper reports a case of skull tumors, unlike other skull tumors, the patients had typical clinical manifestations and imaging findings are not ideal at the same time, considering the history of patients with parotid gland tumor, in the process of diagnosis for us to produce a large disturbance, single-shot, due to the lesions in the exclusion of the patients with other diseases, we decided to surgery was performed in patients with the treatment, The patient's condition improved after surgical treatment and was diagnosed as salivary adenocarcinoma with skull metastasis by pathology. This article summarizes the diagnosis and treatment of the patient, and summarizes some of the author's treatment experience, in order to increase the understanding of the disease, improve the accuracy of diagnosis, and accumulate relevant clinical experience.

Clinical characteristics and surgical outcomes of resectable acinar cell carcinoma of the pancreas-propensity score matching analysis with pancreatic ductal adenocarcinoma.

BACKGROUND: Surgical resection is recommended for patients with resectable acinar cell carcinoma (ACC). The aim of this study was to investigate the clinical characteristics and surgical outcomes of resectable ACC in comparison to pancreatic ductal adenocarcinoma (PDAC). METHOD: A retrospective analysis was performed on all patients who consecutively underwent radical resection with pathologically confirmed ACC and PDAC from December 2011 to December 2018. Clinicopathologic characteristics and follow-up information were analyzed. A 1:3 propensity score matching (PSM) method was used to minimize the bias between ACC and PDAC. RESULTS: A total of 26 patients with ACC and 1351 with PDAC were included. Compared to PDAC, ACC tended to be larger (4.5 vs. 3.0 cm; p < 0.001) and more frequently located in the pancreatic body/tail (61.5% vs. 36.6%, p = 0.009), with lower total bilirubin levels, lower neutrophil lymphocyte ratio (NLR) levels and lower carbohydrate antigen 19-9 (CA19-9) levels and carcinoembryonic antigen (CEA) levels. There was no difference in postoperative morbidities in patients with ACC and PDAC. The median OS and RFS were longer in ACC when compared to PDAC (OS: 43.5 mo vs. 19.0 mo, p = 0.004; RFS: 24.5 mo vs. 11.6 mo, p = 0.023). After the 1:3 PSM, ACC remained to be a better histological type for OS (p = 0.024), but had comparable RFS with PDAC (p = 0.164). CONCLUSION: Patients with ACC after radical resection had better OS than that with PDAC. However, ACC is also an aggressive tumor with a similar trend of RFS with PDAC after the matching, necessitating the multidisciplinary treatment for resectable ACC disease.

Right pneumonectomy for primary large acinic cell carcinoma (AciCC) with severe mediastinal deviation: a case report and literature review.

BACKGROUND: Primary lung acinic cell carcinoma is very rare. Here we report a young female patient who suffered the largest primary lung acinic cell carcinoma with severe mediastinal deviation which has never been reported before. We also reviewed data and features of 20 previously reported cases of primary lung acinic cell carcinoma who underwent lobectomy. CASE PRESENTATION: A 27-year-old female patient presented with recurrent coughing and hemoptysis for more than 10 years came to our hospital. A chest computed tomography (CT) showed a giant space-occupying lesion in the hilum of right lung. After a thorough and detailed preoperative examination, the patient then was performed a radical right pneumonectomy with mediastinal lymph node dissection. The size of the tumor was about 8.6 × 4.5 × 4.4 cm. The pathological results demonstrated a primary acinic cell carcinoma of right lung. The immunohistochemistry of the tumor showed AE1/AE3 (+), Ki-67 (2% +), CK7 (+), Vimentin (+), CK19 (+), α1-ACT (+), AB-PAS (+), S-100 (-), TTF-1 (-). The patient was discharged less than 2 weeks after the operation. So far, the patient has been followed-up for 2 years, and no evidence of tumor recurrence or metastasis was observed. CONCLUSIONS: The primary acinic cell carcinoma of lung in this case is the biggest one ever reported and also the first case treated with radical right pneumonectomy. In addition, the patient had a very rare condition of severe mediastinal deviation at the same time. After surgical treatment, the patient recovered uneventfully and had stable disease without recurrence and metastasis after 2 years of follow-up. This case together with the reported case indicate that primary acinic cell carcinoma of lung is of low malignancy, the prognosis and therapy effect of surgical treatment are relatively satisfactory.

Metastases to the Pituitary Gland: Histological Patterns of Spread and Review of the Literature.

Few studies have focused on histological patterns of metastatic spread to the pituitary gland. We review our experience and that in the literature, 1970-present. Departmental cases, 1998-2021, were assessed for anterior versus posterior gland and/or capsular involvement and cohesive tumor obliterating underlying pituitary architecture versus metastatic cells filling pituitary acini with relative acinar preservation. Eleven autopsy/15 surgical cases, including 2 metastases to pituitary adenomas, were identified. Cohesive/obliterative patterns predominated histologically in both surgical and autopsy cases, but acinar filling by metastatic cells was extensive in 3/26 cases, focal in 5/26, and had resulted in initial erroneous impressions of atypical pituitary adenoma/pituitary carcinoma in 1 case and pituitary adenoma with apoplexy in another, likely due to focusing on necrotic areas in the specimen where the acinar pattern had been broken down and not appreciating nearby areas with acinar filling by metastatic cells. Although most pituitary metastases produce readily identifiable cohesive/obliterative patterns, diagnostic challenges remain with the less frequently seen "acinar filling" pattern. A dichotomy exists between patients with symptomatic pituitary metastases occurring early in the disease course and requiring surgical excision versus patients in whom asymptomatic small pituitary metastases are found incidentally at autopsy, the latter almost invariably in late disease stages, with widely disseminated metastatic disease.

Acinar Cell Carcinoma with Morphological Change in One Month.

A 64-year-old man was admitted to our hospital to undergo examination of a pancreatic tumor accompanied by sudden epigastric pain. The tumor had a well-defined oval shape that was mostly less enhanced, with the exception of part of the tumor on the pancreatic head side, on contrast enhanced (CE)-CT. However, CE-CT performed one-month later revealed that the viable part of the tumor grew toward the pancreatic tail with the reduction of necrotic tissue. We performed distal pancreatectomy and the tumor was diagnosed as acinar cell carcinoma (ACC). One important characteristic of ACC is that it may develop morphological changes within a short period of time.