Skin3D: Detection and longitudinal tracking of pigmented skin lesions in 3D total-body textured meshes

We present an automated approach to detect and longitudinally track skin lesions on 3D total-body skin surface scans. The acquired 3D mesh of the subject is unwrapped to a 2D texture image, where a trained objected detection model, Faster R-CNN, localizes the lesions within the 2D domain. These detected skin lesions are mapped back to the 3D surface of the subject and, for subjects imaged multiple times, we construct a graph-based matching procedure to longitudinally track lesions that considers the anatomical correspondences among pairs of meshes and the geodesic proximity of corresponding lesions and the inter-lesion geodesic distances.We evaluated the proposed approach using 3DBodyTex, a publicly available dataset composed of 3D scans imaging the coloured skin (textured meshes) of 200 human subjects. We manually annotated locations that appeared to the human eye to contain a pigmented skin lesion as well as tracked a subset of lesions occurring on the same subject imaged in different poses. Our results, when compared to three human annotators, suggest that the trained Faster R-CNN detects lesions at a similar performance level as the human annotators. Our lesion tracking algorithm achieves an average matching accuracy of 88% on a set of detected corresponding pairs of prominent lesions of subjects imaged in different poses, and an average longitudinal accuracy of 71% when encompassing additional errors due to lesion detection. As there currently is no other large-scale publicly available dataset of 3D total-body skin lesions, we publicly release over 25,000 3DBodyTex manual annotations, which we hope will further research on total-body skin lesion analysis.     

Seronegative autoimmune diseases: A challenging diagnosis

Autoimmune diseases (AID) are increasingly prevalent conditions which comprise more than 100 distinct clinical entities that are responsible for a great disease burden worldwide. The early recognition of these diseases is key for preventing their complications and for tailoring proper management. In most cases, autoantibodies, regardless of their potential pathogenetic role, can be detected in the serum of patients with AID, helping clinicians in making a definitive diagnosis and allowing screening strategies for early -and sometimes pre-clinical- diagnosis. Despite their undoubted crucial role, in a minority of cases, patients with AID may not show any autoantibody, a condition that is referred to as seronegative AID. Suboptimal accuracy of the available laboratory tests, antibody absorption, immunosuppressive therapy, immunodeficiencies, antigen exhaustion, and immunosenescence are the main possible determinants of seronegative AID. Indeed, in seronegative AID, the diagnosis is more challenging and must rely on clinical features and on other available tests, often including histopathological evaluation and radiological diagnostic tests. In this review, we critically dissect, in a narrative fashion, the possible causes of seronegativity, as well as the diagnostic and management implications, in several AID including autoimmune gastritis, celiac disease, autoimmune liver disease, rheumatoid arthritis, autoimmune encephalitis, myasthenia gravis, Sjögren’s syndrome, antiphospholipid syndrome, and autoimmune thyroid diseases.     

Non-infectious Dacryoadenitis

Dacryoadenitis is an inflammation of the lacrimal gland that may have various etiologies with similar presentations. Despite more recent elucidation of specific causes, the management has remained largely unchanged. Hence, the condition remains under biopsied with the rationale that empirical treatment with corticosteroids is effective for many of the causes. Dacryoadenitis, however, dacryoadenitis can be the presenting sign of an undiagnosed systemic disease and a mimick for lymphoma; hence, tissue diagnosis and systemic investigations play a vital role. A significant proportion of dacryoadenitis has a specific etiology, and IgG4-related dacryoadenitis is more frequently identified as a cause. We summarize the different types of immune-mediated dacryoadenitis, their clinical findings, histopathology, management, and prognosis. We have also highlighted and formulated practice guidelines for diagnosis and effective treatment based on the underlying systemic disease.     

A high-pressure situation

An 8-year-old boy presented with acute visual loss in the right eye and nausea, vomiting, and diplopia. Imaging revealed a right orbital apex mass. Biopsy showed Langerhans cell histiocytosis (LCH), and the patient was diagnosed with isolated orbital LCH causing an orbital apex syndrome. A 12-month cytarabine chemotherapy course was begun, during which the patient developed bilateral optic disc edema. He was diagnosed with cytarabine-induced intracranial hypertension, which was successfully treated with acetazolamide. The cytarabine course was completed with complete resolution of the LCH lesion. The ophthalmologic relevance of this rare disorder is discussed.     

The reality of cholangiocarcinoma in India– real world data from a tertiary referral centre

BackgroundCholangiocarcinomas (CCA) are rare tumours originating from bile duct. Due to their asymptomatic nature they are usually diagnosed when the disease is advanced. Little data exists with respect to their incidence and treatment outcomes in low and middle income countries.MethodA retrospective analysis of a prospectively maintained database of all patients with perihilar (pCCA) and intrahepatic (iCCA) CCA registered between January 2012 and December 2018 was performed.ResultsA total of 760 patients, 427 (56.2%) diagnosed with pCCA and 333 (43.8%) of iCCA were included. Patients with localised, locally advanced and metastatic disease in pCCA were 45.5%, 25.9%, 8.5% and that in iCCA were 22.1%, 10.1% and 67.7% respectively. Only 141 (43.9%, 57 - iCCA, 84 -pCCA) of the total 321 patients started on some definitive cancer directed therapy could complete the intended treatment. The overall curative resection rate for all patients of iCCA was 14.5% whereas for patients of pCCA it was only 10.5%.ConclusionMore than half of CCA patients are not able to complete their intended treatment, being worse for pCCA as compared to iCCA. Early referral and centralisation of treatment for this complex disease might be the way forward to achieve optimal outcomes.