Gallbladder Perforation Into the Peritoneal Cavity.

ABSTRACT: Gallbladder perforation is an uncommon but morbid complication of acute cholecystitis with mural ischemia and necrosis. The most common site of perforation is the fundus because of limited blood supply in this region. The Niemeier classification proposed in 1934 remains the criterion standard in grading gallbladder perforation; type 1 is acute with free perforation into the peritoneal cavity, type 2 is subacute with pericholecystic abscess, and type 3 is chronic with cholecystoenteric fistula. We report a challenging case of type 1 gallbladder perforation due to acute acalculous cholecystitis.

Complete Response to Combination Nivolumab and Ipilimumab in Recurrent Neuroendocrine Carcinoma of the Cervix.

BACKGROUND: Small cell neuroendocrine carcinoma of the cervix is a rare, aggressive tumor treated with a combination of surgery, chemotherapy, and radiation. Survival rates are poor, and innovative therapies are needed. CASE: A 52-year-old woman was diagnosed with small cell neuroendocrine carcinoma of the cervix. Over a 10-year period, she was treated with six different systemic therapeutic regimens, underwent planned hysterectomy with bilateral salpingo-oophorectomy, and received radiation to the pelvis and brain. After a second recurrence of disease, she was treated with a combination of nivolumab and ipilimumab and experienced a complete and durable response. CONCLUSION: The combination of nivolumab and ipilimumab may represent a promising new treatment option for recurrent small cell neuroendocrine carcinoma of the cervix.

Skene's Gland Adenocarcinoma: Borrowing From Prostate Cancer Experience for the Evaluation and Management of a Rare Malignancy.

OBJECTIVE: To determine if adenocarcinoma of the Skene's glands in women, which has a histological and immunohistochemical appearance similar to prostate cancer, can be evaluated and managed with the same tools we use for prostate cancer. METHODS: Serum prostate-specific antigen kinetics, 3D multiparametric (MP) magnetic resonance imaging (MRI), fluciclovine F-18 positron emission tomography (PET), and androgen deprivation therapy (ADT) were employed in a case of Skene's gland adenocarcinoma. RESULTS: The 3D MP MRI clarified the anatomy of the primary lesion and fluciclovine F-18 PET significantly improved our ability to stage the tumor prompting pelvic lymph node dissection that may have otherwise not been performed. ADT resulted in a significant impact on prostate-specific antigen kinetics despite the patient having a testosterone level in the normal range for a postmenopausal woman. CONCLUSION: Despite the rarity of Skene's gland adenocarcinoma, we can employ many of the tools at our disposal for the evaluation and management of prostate cancer to benefit the women found to have this malignancy.

18F-fluorodeoxyglucose positron emission tomography/computed tomography in predicting overall survival of oral cavity squamous cell carcinoma: Ongoing controversy.

We aimed to retrospectively determine if initial staging 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/ CT) can predict overall survival (OS) in oral cavity squamous cell carcinoma (OCSCC), which is currently a source of ongoing controversy in the literature. Forty-six consecutive patients with nonmetastatic (Stage M0) OCSCC had 18F-FDG PET/CT prior to definitive surgical treatment followed by observation or adjuvant treatment at our institution between 2006 and 2012. The median follow-up time was 18 months (range 0.1-76 months). Univariate and multivariate analysis were used to determine the ability of imaging, pathologic, and demographic factors to predict OS. 18F-FDG PET/CT parameters were standardized uptake value (SUV) maximum and mean, metabolic tumor volume, and total lesional glycolysis (TLG) of primary tumor and regional nodes. Significant predictors of OS in the multivariate analysis were primary tumor SUV mean, nodal TLG, and age. Two-year OS of patients with primary tumor SUV mean below and above the median of 6.26 was 68% and estimated 28%, respectively. Two-year OS of patients with nodal TLG below and above median of 7.9 was 69% and 34%, respectively. Two-year OS of patients younger and older than median age of 57 was 60% and 43%, respectively. Our results suggest that 18F-FDG PET/CT may be a valuable addition to multifactorial models predicting outcome for OCSCC. Thus, continued research aiming to incorporate 18F-FDG PET/CT parameters in risk-stratification algorithms for OCSCC is warranted and should be conducted using more standardized prognostic models driven by a specific clinical question.

Head and Neck Cancer Soft Tissue Radiation Necrosis-Diagnostic Challenge.

A 53-year-old man with T4aN2cM0 tongue base squamous cell carcinoma received definitive chemoradiation. FDG PET/CT at 6 weeks showed partial metabolic response with soft tissue air indicating radiation necrosis at primary site and complete response in the neck. At 9 weeks, contrasted CT showed worsening but nonenhancing ulceration, area biopsied demonstrating a minute carcinoma focus with treatment effect. At 12 weeks, PET/CT showed increased primary site uptake interpreted as disease progression; however, no viable tumor was found at salvage surgery. Because nonenhancing ulceration predicts pure radiation necrosis with no viable tumor, contrasted CT may guide treatment selection in challenging cases.

Identification of distant metastases with positron-emission tomography-computed tomography in patients with previously untreated head and neck cancer.

OBJECTIVES: To investigate the utility of positron-emission tomography-computed tomography (PET-CT) in identifying distant metastatic disease in patients with previously untreated head and neck squamous cell cancer (HNSCC) prior to definitive treatment. MATERIALS AND METHODS: Retrospective analysis of 27 consecutive patients with previously untreated HNSCC who underwent PET-CT imaging in addition to chest radiography (CXR) as part of their metastatic workup. RESULTS: The majority of patients (89%) had TNM stage III or IV disease. PET-CT was suspicious for pulmonary malignancy in four (15%) patients and indeterminate in one (4%) patient. CXR was suspicious for pulmonary malignancy in two (7%) patients. Pulmonary metastases or a new lung primary was present in 3 (11%) patients: 3 of 4 (75%) patients with positive PET-CT scans and 0 of 23 (0%) patients with negative or indeterminate PET-CT scans compared with 2 of 2 (100%) patients with positive CXR and 1 of 25 (4%) patients with negative CXR. The sensitivity and specificity of PET-CT in predicting pulmonary malignancy was 100% and 96%, respectively, with a positive predictive value of 75% and a negative predictive value of 100%. The sensitivity and specificity of CXR in predicting pulmonary malignancy was 67% and 100%, respectively, with a positive predictive value of 100% and a negative predictive value of 96%. Including nonpulmonary sites, the overall incidence of distant metastatic disease was 19% (5/27) with 11% (3/27) unsuspected prior to PET-CT. CONCLUSIONS: PET-CT improves detection of metastatic disease in the high-risk patient and should be performed as part of the routine pretreatment evaluation of patients with advanced stage HNSCC.

Malignancy in kaolin pneumoconiosis found with F-18 FDG positron emission tomography.

Kaolin pneumoconiosis may produce radiologic findings similar to those of malignancy. Current management includes serial radiologic examination and lung sampling of suspicious parenchymal opacities and nodules to exclude associated malignancy. This may result in unnecessary pulmonary resections in patients with already compromised lung function. In a patient with known kaolin pneumoconiosis and multiple nodules, we used positron emission tomography to identify suspicious areas for malignancy that were confirmed by open lung biopsy, leading to successful lung cancer treatment.

Hepatic Hemangioma on SPECT Myocardial Perfusion Imaging.

Extracardiac uptake on SPECT MPI, seen with physiologic radiotracer distribution, benign or malignant neoplasm, infection, inflammation, or granulomatous disease, may confound the accuracy of MPI or lead to unsuspected pathology. A 38-year-old woman with end-stage renal disease on hemodialysis had SPECT MPI for renal transplant preoperative risk stratification, showing left anterior descending artery ischemia and an intense extracardiac soft tissue focus adjacent to the diaphragmatic right ventricle concerning for focal infection related to prior coronary or gastric surgeries or tumor. CT revealed focal herniation of liver containing a flash-fill hemangioma into the left hemithorax accounting for this focal uptake.

Functional imaging in temporal lobe epilepsy.

This article highlights the importance of functional imaging methods in the diagnosis and preoperative planning in temporal lobe epilepsy TLE). It starts with a discussion of the role of ictal and interictal single-photon emission computed tomography (SPECT) and interictal positron emission tomography (PET) in lateralizing TLE. The next section discusses the role of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) and perfusion MRI, particularly for lateralization of language and memory in TLE patients. The final section explores the relatively new role that the emerging technique of diffusion tensor imaging (DTI) is playing in the evaluation of TLE.

FDG-PET Identification of Infected Pulmonary Artery Conduit Following Tetralogy of Fallot (TOF) Repair.

Tetralogy of Fallot (TOF) is one of the most common forms of cyanotic congenital heart disease usually managed by serial surgical repairs. The repaired prosthetic valve or conduit is susceptible to life-threatening infection. FDG-PET is an effective alternative to evaluate the source of infection when other examinations are inconclusive. We report an unusual case of an infected pulmonary artery conduit after TOF repair although the echocardiogram was negative for vegetation, which was later confirmed by surgery and pathology. The case highlights the role of FDG-PET as a problem-solving tool for potential endocarditis and cardiac device infection cases after complex cardiac surgery.

The Role of Fluorodeoxy-D-glucose Positron Emission Tomography/Computed Tomography in Nodal Staging of Nonsmall Cell Lung Cancer in Sequential Surgical Algorithm.

With nonsmall cell lung cancer (NSCLC), accurate mediastinal nodal staging is crucial to determine whether a patient is or is not a surgical candidate. Traditionally, computed tomography (CT) and fluorodeoxy-D-glucose (FDG) positron emission tomography (PET)/CT are the initial steps followed by tissue sampling through mediastinoscopy and/or thoracotomy, which are invasive procedures. There is controversy regarding the possibility of omission of the invasive diagnostic procedures and solely relying on noninvasive presurgical staging CT and FDG PET/CT results. Eighty-three patients who had PET/CT, mediastinoscopy, and thoracotomy for NSCLC were analyzed. For all lymph nodes that may be sampled by mediastinoscopy, PET/CT sensitivity was 80%, specificity was 86%, positive predictive value was 47%, and negative predictive value (NPV) was 97%; and for those in this group whose clinical stage was T1/T2 M0, sensitivity was 100% and specificity was 84%. For lymph nodes accessible only at thoracotomy, sensitivity was 42% and specificity was 88%. FDG PET/CT is accurate in assessing stations 2R/L, 4R/L, and 7 nodes and has the potential to replace mediastinoscopy in the treatment algorithm of T1/T2 M0 disease. A negative PET/CT may potentially prevent the patient from invasive mediastinoscopy given its high NPV. However, a patient with positive PET/CT should undergo tissue biopsy with pathology confirmation.

Unusual Contiguous Soft Tissue Spread of Advanced Malignant Mesothelioma Detected by FDG PET/CT.

Malignant pleural mesothelioma (MPM) is a tumor of mesodermal origin that arises from the serosa of the pleura, peritoneum, pericardium or tunica vaginalis. MPM is well known to have a poor prognosis with a median survival time of 12 months. Accurate diagnosis, staging and restaging of MPM are crucial with [18F] flurodeoxy-D-glucose positron emission tomography (FDG PET/CT) playing an increasingly important role. Here we report a case of MPM with unusual contiguous soft tissue spread of the tumor along the dermal and fascial planes characterized by PET/CT. Given that the loco-regional tumor in the thorax was under control on PET/CT, the death of the patient was most likely associated with physiologic or metabolic causes associated with an extra-thoracic tumor.

Nuclear Protein in Testis Midline Carcinoma Presenting in an Infant as a Pericardial Mass with Staging by 18F-Fluorodeoxyglucose-positron Emission Tomography/Computed Tomography.

Nuclear protein in testis (NUT) midline carcinoma (NMC) is a rare, aggressive, lethal, epithelioid, poorly differentiated cancer first described in Japan in 1991, unique in that is defined genetically rather than by histological tissue of origin. It usually arises in the body midline and presents as a mass with metastasis. An infant presenting with pneumonia was found to have a pericardial mass, NMC resected, and subsequent staging positron emission tomography (PET) showing residual mediastinal tumor and midline abdominal metastases. Fewer than 100 cases of NMC have been reported in the literature, and PET appears to be the imaging modality of choice in complete staging and evaluation of treatment response.

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia and Granulomatous Inflammation Mimicking High-Grade Malignancy on FDG-PET/CT.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare form of preinvasive lung lesion associated with indolent carcinoid tumor formation. This disease is characterized by multiple small pulmonary nodules with low SUVmax on F-FDG PET. Biopsy and immunohistochemical staining for neuroendocrine markers confirm diagnosis. There is no consensus for treatment, which typically involves surgical excision or management of symptoms with steroid-based therapies. We report an unusual case of DIPNECH colocalizing with necrotizing granulomatous inflammation mimicking high-grade aggressive malignancy on FDG-PET and a typical case of DIPNECH for comparison with low FDG avidity.