Metastatic tumors to the pancreas: Balancing clinical impression with cytology findings.

BACKGROUNDS/AIMS: Metastatic lesions of the pancreas (PMET) account for 1%-5% of all malignant solid pancreatic lesions (SPL). In this study we evaluated the utility of endoscopic ultrasonography with fine needle aspiration (EUS-FNA) in diagnosing PMET. METHODS: Patients who underwent EUS-FNA at a community referral center between 2011-2017 for SPL were identified. Clinical, radiologic, and EUS-FNA features of those with PMET were compared to those with primary solid tumors of the pancreas: pancreatic adenocarcinoma (PDAC) and neuroendocrine tumors (PNET). RESULTS: A total of 191 patients were diagnosed with solid pancreatic malignancy using EUS-FNA: 156 PDAC, 27 PNET, and eight (4.2%) had PMET. Patients with PMET were less likely to have abdominal pain (25.0% vs. 76.3% vs. 48.2%; p < 0.01) or obstructive jaundice (37.5% vs. 58.3% vs. 0%; p < 0.01) compared to PDAC and PNET. Those with PMET were more likely to have mass lesions with/without biliary or pancreatic ductal dilatations (100% vs. 86.5% vs. 85.2%; p < 0.01) and lower CA19-9 (82.5 ± 43.21 U/mL vs. 4,639.30 ± 11,489.68 U/mL vs. 10.50 ± 10.89 U/mL; p < 0.01) compared to PDAC and PNET. Endosonographic features were similar among all groups. Seven (87.5%) patients with PMET had a personal history of malignancy prior to PMET diagnosis. The primary malignancy was renal cell carcinoma in five PMET. CONCLUSIONS: PMET are exceedingly rare, comprising less than 5% of SLP. Patients with PMET are less likely to present with symptoms and mostly identified by surveillance imaging for the primary malignancy.

A Rare Case of Primary Pulmonary Adenoid Cystic Carcinoma and the Diagnostic Challenges on Cytology.

Adenoid cystic carcinoma (ACC) is a malignancy that typically arises in the salivary gland, yet can occur in other anatomic sites, including the lung. Primary pulmonary ACC is rare and comprises approximately 0.04-0.2 percent of all lung cancers. These tumors have the potential to recur and metastasize and are refractory to chemotherapy and radiation. Though histopathologic features are identical to ACC seen in the salivary glands on tissue biopsy, diagnosis on cytology specimens is challenging, as cytopathologic features of this entity have not been collectively described due to its low incidence and limited reports of the disease. We report a case of primary pulmonary ACC in a 43-year-old female that was missed on cytology, but was recognized on subsequent transbronchial biopsy. The biopsy revealed a neoplasm with cribriform architecture composed of round myoepithelial cells with inconspicuous nucleoli (see Figures 3 and 4). When correlating with the cytology specimen, the rare clusters of monomorphic, round cells with hyperchromatic nuclei, small nucleoli, and increased nuclear to cytoplasmic ratio (see Figures 1 and 2) were supportive of ACC, based on findings described from other reported cases. A small amount of homogenous, eosinophilic hyaline material was also associated with the neoplastic cells (see arrows in Figure 1). This case emphasizes the need to continue documenting cases of primary pulmonary ACC to expand the medical literature and increase awareness of this rare neoplasm in order to allow for accurate identification in cytologic specimens, especially when tissue biopsy is not obtained.

Finding a needle in a haystack: Endoscopic ultrasound-guided fine-needle aspiration for solid pancreatic masses in the setting of chronic pancreatitis.

BACKGROUND: The mainstay for the definitive diagnosis of pancreatic lesions is endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). However, there is evidence that EUS-FNA has low sensitivity in the setting of chronic pancreatitis (CP). This single-center retrospective study aimed to compare and analyze the diagnostic yield of EUS-FNA for solid pancreatic lesions in the presence and absence of CP, and to further investigate strategies for overcoming the low diagnostic yield in the setting of CP. METHODS: This study identified patients who underwent EUS-FNA at Sanford USD Medical Center (SD, USA) for a solid pancreatic lesion between July 15, 2011, and November 30, 2017. Data on demographics, clinical features, cross-sectional imaging findings, EUS findings, cytology/pathology, and clinical follow up were collected. RESULTS: The final diagnosis was adenocarcinoma in 156 patients (67%), neuroendocrine tumor in 27 (12%), lymphoma in 6 (3%), metastatic malignancy in 8 (4%), and benign etiologies in 35 (15%). CP was identified in 44/234 (19%) patients. The overall diagnostic sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for EUS-FNA were 92.9%, 97.1%, 99.5%, 70.8%, and 93.5%, respectively. The sensitivity (80% vs. 95%, P=0.020) and accuracy (86% vs. 95%, P=0.043) were significantly lower in patients with CP compared to those without CP. CONCLUSION: CP can significantly affect the EUS-FNA diagnostic yield of solid pancreatic neoplasms. A high index of clinical suspicion is required in these cases to make a definitive diagnosis.

Diagnostic Challenge With Auto-Immune Pancreatitis and IgG4-Related Disease.

IgG4-related disease (IgG4RD) is a chronic immune mediated condition primarily affecting the hepato-pancreatico-biliary system. We report a case of IgG4RD with extensive pancreatic and hepatic involvement masquerading as metastatic pancreatic malignancy posing a diagnostic and therapeutic dilemma.

An Incidental Finding of Paratesticular Malignant Mesothelioma During Operation for Hydrocelectomy.

Paratesticular malignant mesothelioma is a rare and potentially aggressive malignancy, accounting for approxi- mately 0.3-1.4 percent of all malignant mesotheliomas. The tumor presents as a painless scrotal mass associated with recurrent hydrocele. We report an incidental case of paratesticular malignant mesothelioma in a 73-year- old man that was found during an operation to remove a progressively enlarging, symptomatic hydrocele. During the procedure the surgeon noted multiple, irregular, extratesticular masses, and subsequently submitted a sam- ple for frozen section analysis. Frozen section assessment revealed a papillary-appearing, malignant tumor and the surgeon proceeded with a radical orchiectomy. Examination of the orchiectomy specimen revealed multiple, yellow-white, papillary, exophytic excrescences that tracked along the hydrocele and coursed up the tunica vagi- nalis of the spermatic cord. Microscopically, the tumor was composed of papillary fronds and nests of malignant cells with enlarged, hyperchromatic, pleomorphic nuclei. Pankeratin and calretinin immunohistochemical stains strongly highlighted the tumor cells, supporting the diagnosis of malignant mesothelioma. Suspicion of malignant mesothelioma as a differential diagnosis in the setting of enlarging hydrocele is imperative, as the care of the patient is dramatically altered to address the aggressive nature of the disease and the unfavorable outcome.