Adult Pulmonary Blastoma: A Case Report with Spectrum of Rare Manifestations.

Pulmonary blastoma (PB) is an exceedingly rare and aggressive malignant lung neoplasm that has distinct biphasic morphology. In this report, we document rare manifestations and molecular alterations in PB. A 59-year-old non-smoker female, presented with cough and hemoptysis for 4 months. The high-resolution computed tomography chest scan showed a 3.5x2.7 cm mass in the basal segment of the left lung. Positron emission tomography and computed tomography revealed a fluorodeoxyglucose avid lobulated mass in the superior segment of the lower lobe of the left lung. On core biopsy, the diagnosis of pleomorphic carcinoma in a background of adenocarcinoma was made. A definite diagnosis of pulmonary blastoma was established on the left lung lobectomy specimen based on morphological and immunohistochemical findings. Post-surgical biopsy from the scalp swelling showed metastatic deposits. On Next Generation Sequencing (NGS), in addition to conventional CTNNB1 gene mutation, new pathogenic MYCN and ATM gene mutations were detected. Post-chemotherapy, the patient was doing well after 10 months of close follow-up. PB exhibited rare associations in the form of non-smoker status, scalp metastasis, and MYCN and ATM gene mutations on NGS in addition to conventional CTNNB1 gene mutation. Large cohort studies are required to discover the incidence, significance and therapeutic implications of these co-existing pathogenic molecular alterations in PB.

The WHO system versus the Papanicolaou society of cytopathology system for reporting pancreaticobiliary cytology for risk stratification-which is better?

BACKGROUND: Recently, the World Health Organization (WHO) has proposed a reporting system for pancreaticobiliary cytopathology. We applied this classification for pancreatic lesion samples by fine needle aspiration (FNA) and compared the results to the previous classification of the Papanicolaou Society of Cytopathology (PSC) system for risk stratification. METHODS: The computerized database was searched for all pancreatic endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and transabdominal ultrasound-guided FNA (TUS-FNA) samples from 2016 to 2020 and cases were reassigned as per the PSC and the WHO diagnostic categories. Cases with follow-up, clinicoradiological, and/or histopathology were included in the study. The risk of malignancy (ROM) was calculated across all diagnostic categories based on clinical data, imaging data, and histopathology wherever available. RESULTS: There were a total of 625 pancreatic FNA. In 230 cases, follow-up information was available which included 116 EUS and 114 TUS-FNA samples. The ROM for PSC categories I-VI was 40%, 19.7%, 28.6%, 57.1%, 94.7%, and 97.9% and for the WHO categories (I-VII), it was 60%, 21.3%, and 35.7%, not representative, not applicable, 94.7% and 94.9%. The overall sensitivity and specificity of PSC was 68.2% and 96.2% when categories V and VI were taken as positive and 78.9% and 93.3% for WHO when categories VI and VII were taken as positive. CONCLUSIONS: Pancreatic FNA samples reported as per the WHO system showed better sensitivity as compared to the PSC system resulting in better risk stratification and consequently better patient management. The overall high specificity and moderate sensitivity reaffirm the utility of FNA in pancreatic lesions.

Cytology as the guiding light: Prompt cytomorphologic diagnosis of cystic metastases from a jejunal neuroendocrine tumor masquerading as hepatic abscesses.

Hepatic cystic lesions are commonly seen in radiology and can occur due to infective or neoplastic causes. It is imperative to determine the precise nature of these hepatic cysts owing to significant therapeutic and prognostic differences. Hepatic metastases from gastrointestinal neuroendocrine tumors (NETs) mostly present as solid hypervascular lesions. Cystic presentation of the metastatic NETs is extremely rare. A 64-year-old woman presented with an abdominal lump of 3 months duration and high-grade fever from the last 2 days. An ultrasound abdomen revealed multiple hypoechoic liver lesions suggestive of liver abscesses. An ultrasound-guided fine-needle aspiration (FNA) from the cystic liver lesions revealed a NET confirmed by immunocytochemistry. The Ki-67 index was 5%; hence, a final diagnosis of metastatic NET, grade 2, was given with advice to work up for localizing the primary tumor. Subsequently, a contrast-enhanced computerized tomography of the abdomen revealed a polypoidal lesion in the proximal jejunum, which showed intense expression on the whole-body DOTANOC scan (SUVmax-76.5), indicating it to be the likely primary tumor along with somatostatin receptor-expressing multiple lymph nodes and hypodense liver lesions. Thus, a final diagnosis of a jejunal NET with abdominal lymph node and liver metastases was made. The present report highlights the importance of FNA as a reliable modality in diagnosing metastatic NETs presenting as unusual cystic hepatic metastases masquerading as liver abscesses. Additionally, the cell block helps confirm the cytologic diagnosis and enables upfront tumor grading, thereby helping in prognostication and therapeutic decision-making.

68Ga-DOTA-Exendin PET-MRI Fusion Imaging in a Case of Insulinoma.

Persistent hyperinsulinemic hypoglycemia in adults is most commonly caused by insulinomas, which pose a diagnostic challenge to physicians, surgeons, and radiologists and require multimodality imaging for precise localization and staging. PET tracers such as F-FDOPA and glucagon-like peptide 1 receptor analogs have been used for imaging insulinomas. Glucagon-like peptide 1 receptor analogs have recently shown promising results in preoperative localization of these tumors, as all insulinomas express glucagon-like peptide 1 receptors. Ga-DOTA-Exendin PET and MRI done in the present case helped in precise localization and management of the culprit lesion, whereas contrast-enhanced CT and F-FDOPA PET failed to do so.

Role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in restaging and prognosis of recurrent melanoma after curative surgery.

Malignant melanoma is a highly aggressive tumor and surgical resection is the primary treatment. However, the chances of recurrence are quite high despite complete resection. The aim of study was to evaluate the 18F-fluorodeoxyglucose(18F-FDG) positron emission tomography-computed tomography (PET/CT) in detection of recurrent melanoma after curative surgery and its prognostic value. Fifty-four melanoma patients (32 women) with prior primary lesion resection were evaluated with 18F-FDG PET/CT for clinically suspicious recurrent disease. The diagnostic accuracy of 18F-FDG PET/CT (visual interpretation as well as semi-quantitative parameter) was determined on the basis of subsequent imaging and clinical follow-up. Melanoma-specific survival and risk of progression (hazard ratio [HR]) were assessed using Kaplan-Meier method and Cox regression analysis. 18F-FDG PET/CT detected recurrent diseases in 36 (66%) patients including distant metastases in 13 patients and second synchronous malignancy in 2 patients. Overall, the sensitivity, specificity, positive predictive value, and negative predictive value of 18F-FDG PET/CT were 91.2%, 80.0%, 88.6%, and 84.2%, respectively, with area under the curve of 0.86 (95% confidence interval: 0.74-0.97; P < 0.05). Positive 18F-FDG PET/CT study was associated with a significantly shorter overall survival than negative study (30.8 ± 4.6 vs. 64.5 ± 6.9 months, P < 0.05). Apart from positive 18F-FDG PET/CT scan, maximum standardized uptake value (SUVmax) >2.7 and combination of both were independently associated with an increased risk of disease progression (HR = 7.72, 21.58, and 11.37, respectively; P < 0.05). 18F-FDG PET/CT showed enhanced diagnostic performance in patients with suspicious recurrent malignant melanoma leading to appropriate management. FDG positivity along with SUVmax >2.7 provides important prognostic value in predicting the survival outcomes and assessing the risk of disease progression.

18F-FDG-Labeled Autologous Leukocyte PET-CT in a Patient With Aortic Valve-Tube Graft Infection After Bentall Procedure.

Infection of aortic valve-tube graft, although rare, is associated with high morbidity and mortality. Early identification of site and extent of infection is not only challenging but also crucial for adequate patient management and prognostication of disease. Combined clinical, laboratory investigation and imaging modalities assist in the identification of aortic valve graft infection. Molecular imaging techniques like PET/CT using F-FDG and F-FDG-labeled autologous leukocytes (LALs) have improved the sensitivity for detection of infection, resulting in better outcome for these patients. F-FDG-labeled autologous leukocyte PET/CT in our patient after Bentall procedure accurately localized the site and extent of infection.

Incidental Detection of Plasma Cell Neoplasm on 18F-Choline PET/CT Imaging.

F-Fluorocholine is a relatively new, extremely versatile radiotracer for detecting proliferative or mitogenic activity. Its diagnostic potential has been explored in cancers of the prostate, liver, esophagus, breast, brain, and lung, as well as lymphoma, sarcoma, melanoma, and parathyroid adenomas. The authors present a case where fluorocholine PET/CT performed for characterizing a space-occupying lesion in the brain revealed intensely tracer-avid skull lesions with intracranial soft tissue component and multiple other skeletal lesions. Fine-needle aspiration cytology from the skull and chest wall lesions confirmed the diagnosis of plasma cell neoplasm.

Nonspecific Uptake of 68Ga-Prostate-Specific Membrane Antigen in Diseases other than Prostate Malignancy on Positron Emission Tomography/Computed Tomography Imaging: A Pictorial Assay and Review of Literature.

68Ga-labeled prostate-specific membrane antigen (PSMA) ligand positron emission tomography/computed tomography imaging (PET/CT) is a rapidly evolving imaging modality for prostate cancer. Many studies have proved its superiority in staging, restaging, and detecting the recurrent prostate cancer. However, case reports describing the incidental tracer uptake in benign and nonprostatic malignancies are also reported in the literature, thus questioning the specificity of the tracer. This pictorial assay illustrates the nonspecific tracer uptake encountered during PSMA PET/CT imaging, knowledge of which can increase the confidence of interpreting physicians and may also open a new path for peptide receptor radionuclide therapy in nonprostatic malignancies.

68Ga-Prostate-Specific Membrane Antigen PET/CT and 18F-FDG PET/CT of Primary Signet Ring Cell Breast Adenocarcinoma.

Primary signet ring cell adenocarcinoma of the breast is a rare neoplasm. Similar to other mucinous neoplasms, it has low FDG avidity and poor prognosis compared with the traditional ductal/lobular carcinomas. We present a case of a 40-year-old woman with signet ring cell adenocarcinoma and skeletal fluorosis showing higher uptake of Ga-prostate-specific membrane antigen in the primary lesion and the metastatic sites compared with F-FDG on PET/CT imaging. Additionally, diffuse increased prostate-specific membrane antigen uptake was noticed in the entire skeleton, likely due to skeletal fluorosis.

Ectopic Cushing Syndrome (ECS): 68Ga-DOTANOC PET/CT Localizes the Site of Ectopic Adrenocorticotropic Hormone Production.

Ectopic Cushing syndrome constitutes approximately 10% of all patients with Cushing syndrome. The clinical features of hypercortisolism result from elevated levels of adrenocorticotropic hormone produced by a tumor. The present case presented with clinical and biochemical parameters suggestive of Cushing syndrome with normal pituitary and adrenals on imaging. Ga-DOTANOC PET/CT done to localize an ectopic adrenocorticotropic hormone-producing tumor revealed metastatic medullary carcinoma of the thyroid as the culprit lesion.

Dual Pathologies of Parathyroid Adenoma and Papillary Thyroid Cancer on Fluorocholine and Fluorodeoxyglucose PET/CT.

18F-Fluorocholine (FCH) PET/CT is evolving as a functional imaging modality for the preoperative imaging of abnormal parathyroid tissue(s) helping to localize eutopic and ectopic parathyroid tissue and limit the extent of surgery. FCH PET/CT may show incidental uptake in various thyroid lesions necessitating further evaluation, whereas the role of 18F-fluorodeoxyglucose (FDG) PET/CT in the detection of incidental thyroid nodules is well documented. The case of a middle-aged woman with dual pathology of parathyroid adenoma and papillary thyroid cancer detected on FCH and FDG PET/CT is presented.

Erratum to: Dual Pathologies of Parathyroid Adenoma and Papillary Thyroid Cancer on Fluorocholine and Fluorodeoxyglucose PET/CT.

[This corrects the article DOI: 10.1007/s13139-017-0488-3.].

Incidental Detection of Type B2 Thymoma on 68Ga-Labeled Prostate-Specific Membrane Antigen PET/CT Imaging.

Ga-labeled prostate-specific membrane antigen is a novel radiotracer for imaging of prostate cancer. We report a hormonally treated patient with prostate carcinoma, presenting with lower urinary tract symptoms and rising prostate-specific antigen levels, who underwent Ga-labeled prostate-specific membrane antigen PET/CT for suspected recurrence. No tracer avid lesion was noted in the prostate gland and locoregional area. However, intense tracer avid heterogeneously enhancing soft tissue lesion with cystic areas and coarse calcifications was seen in the anterior mediastinum. PET/CT-guided biopsy from the mediastenal lesion revealed type B2 thymoma.