Tardigrade and Manifold Sign: Two New Signs in Dupuytren's Disease.

Dupuytren's disease (DD) is a chronic benign fibroproliferative disorder of the palmar and digital fasciae. It is characterized by formation of nodules and fibrous cords that may eventually lead to contractures with permanent flexion of the finger joints. Correction of the flexion contractures in advanced disease is still performed by open limited fasciectomy; ultrasonography (US)-guided minimally invasive treatment is preferred for early disease.We provide an overview of the detailed anatomy of the palmar aponeurosis and the structures that may be involved in DD. Although magnetic resonance imaging is used as the gold standard, these small anatomical structures are often better visible on US. We describe two new morphological signs due to thickening of these small structures in patients with DD: the tardigrade sign and the manifold sign. Familiarity with detailed imaging anatomy and these new imaging signs of DD will help confirm a correct and early diagnosis and distinguish this disease from various other entities.

Molecular profiling in lung cancer associated with cystic airspaces.

'Lung cancer associated with cystic airspaces' is a rare radiological entity that is more frequently encountered on imaging studies and is gaining more attention since the widespread use of CT for lung cancer screening. Numerous aspects of this entity remain unraveled, including molecular profiling. The goal of this observational retrospective single-center case series is to investigate the molecular profile of lung cancers presenting with this specific morphology in a Caucasian population. Between January 2014 and May 2017, 13 patients were presented at the Multidisciplinary Thoracic Oncology Tumor Board with imaging findings consistent with 'lung cancer associated with cystic airspaces'. Electronic medical files were reviewed for patient characteristics, stage, histopathological findings and - in particular - molecular profiling. Histopathological diagnosis showed adenocarcinoma in 11 patients in our series. Mutational analysis in 10 showed different molecular alterations: an EGFR exon 18 mutation, ROS1 rearrangement and BRAF mutation in one patient each. Two patients showed KRAS mutations. With 5 out of 10 patients with an adenocarcinoma presenting with cystic airspace morphology showing a molecular alteration, this may indicate that in this subgroup, molecular profiling is mandatory, regardless of smoking history.

Mediastinal mass in a young man with a previous history of dermatofibrosarcoma protuberans: metastatic disease or different entity-a case report.

A 34-year-old man presented to the clinician with a persisting cutaneous swelling in the lower back. Diagnosis of dermatofibrosarcoma protuberans (DFSP) was made based on histopathologic examination of the resected mass and molecular testing. Further diagnostic workup with computed tomography (CT) showed a mass in the prevascular mediastinum, composed of a soft tissue component, areas of fat density and some small foci of calcification. Location of the mass and typical imaging findings of fat component and calcification were suggestive for a teratoma. Robotic assisted surgery with complete resection of the mediastinal mass was performed. Histopathological examination showed that there was no relationship with the primary tumor and confirmed the diagnosis of a teratoma. Teratomas are to be classified as mature, immature and teratomas with malignant transformation. In this patient, histopathology shows a teratoma with somatic-type malignancy. The patient was treated with adjuvant radiotherapy. Upon progressive disease with lung metastasis, pleural metastasis and lymph node metastasis, palliative chemotherapy was started. Knowledge of classic metastatic patterns is essential in imaging oncologic patient. Since DFSP rarely metastasizes, a metastatic origin of the mediastinal mass would not be likely. In a patient with typical imaging findings of a mature teratoma, associated findings such as adenopathy and pulmonary nodules should alert the radiologist to the possibility of a teratoma with somatic-type malignancy.

Diagnostic and clinical features of lung cancer associated with cystic airspaces.

"Lung cancer associated with cystic airspaces" is an uncommon manifestation, in which lung cancer presents on imaging studies with a cystic area with associated consolidation and/or ground glass. With the widespread use of computed tomography (CT), both in clinical practice and for lung cancer screening, these tumors are being more frequently recognized. An association of this entity with smoking has been established with the majority of cases reported being in former and current smokers. The true pathogenesis of the cystic airspace is not yet fully understood. Different causes of this cystic airspace have been described, including a check-valve mechanism obstructing the small airways, lepidic growth of adenocarcinoma on emphysematous lung parenchyma, cyst formation of tumor and tumor growth along the wall of a pre-existing bulla. Adenocarcinoma is the commonest histological type, followed by squamous cell carcinoma. Two classification systems have been described, based on morphological features of the lesion, taking into account both the cystic airspace as well as the morphology of the surrounding consolidation or ground glass. The cystic component may mislead radiologists to a benign etiology and the many different faces on imaging can make early diagnosis challenging. Special attention should be made to focal or diffuse wall thickening and consolidation or ground glass abutting or interspersed with cystic airspaces. Despite their atypical morphology, staging and management currently are still similar to that of other lung cancer types. Although the rarity of this entity will hamper larger studies, numerous aspects regarding this particular lung cancer type still need to be unraveled. This manuscript reviews the CT-imaging findings and gives an overview of available data in the English literature on pathogenesis, histopathology and clinical findings. Differential diagnosis and pitfalls are discussed as well as future directions regarding staging and management.

Evaluation of the solitary pulmonary nodule: size matters, but do not ignore the power of morphology.

Subsequent to the widespread use of multidetector computed tomography and growing interest in lung cancer screening, small pulmonary nodules are more frequently detected. The differential diagnosis for a solitary pulmonary nodule is extremely broad and includes both benign and malignant causes. Recognition of early lung cancers is vital, since stage at diagnosis is crucial for prognosis. Estimation of the probability of malignancy is a challenging task, but crucial for follow-up and further work-up. In addition to the clinical setting and metabolic assessment, morphological assessment on thin-section computed tomography is essential. Size and growth are key factors in assessment of the malignant potential of a nodule. The likelihood of malignancy positively correlates with nodule diameter: as the diameter increases, so does the likelihood of malignancy. Although there is a considerable overlap in the features of benign and malignant nodules, the importance of morphology however should not be underestimated. Features that are associated with benignity include a perifissural location and triangular morphology, internal fat and benign calcifications. Malignancy is suspected in nodules presenting with spiculation, lobulation, pleural indentation, vascular convergence sign, associated cystic airspace, bubble-like lucencies, irregular air bronchogram, and subsolid morphology. Nodules often show different features and combination of findings is certainly more powerful. TEACHING POINTS: • Size of a pulmonary nodule is important, but morphological assessment should not be underestimated. • Lung nodules should be evaluated on thin section CT, in both lung and mediastinal window setting. • Features associated with benignity include a triangular morphology, internal fat and calcifications. • Spiculation, pleural retraction and notch sign are highly suggestive of a malignant nature. • Complex features (e.g. bubble-like lucencies) are highly indicative of a malignant nature.