Man against machine reloaded: performance of a market-approved convolutional neural network in classifying a broad spectrum of skin lesions in comparison with 96 dermatologists working under less artificial conditions

BACKGROUND

Convolutional neural networks (CNNs) efficiently differentiate skin lesions by image analysis. Studies comparing a market-approved CNN in a broad range of diagnoses to dermatologists working under less artificial conditions are lacking.

MATERIALS AND METHODS

One hundred cases of pigmented/non-pigmented skin cancers and benign lesions were used for a two-level reader study in 96 dermatologists (level I: dermoscopy only; level II: clinical close-up images, dermoscopy, and textual information). Additionally, dermoscopic images were classified by a CNN approved for the European market as a medical device (Moleanalyzer Pro, FotoFinder Systems, Bad Birnbach, Germany). Primary endpoints were the sensitivity and specificity of the CNN's dichotomous classification in comparison with the dermatologists' management decisions. Secondary endpoints included the dermatologists' diagnostic decisions, their performance according to their level of experience, and the CNN's area under the curve (AUC) of receiver operating characteristics (ROC).

RESULTS

The CNN revealed a sensitivity, specificity, and ROC AUC with corresponding 95% confidence intervals (CI) of 95.0% (95% CI 83.5% to 98.6%), 76.7% (95% CI 64.6% to 85.6%), and 0.918 (95% CI 0.866-0.970), respectively. In level I, the dermatologists' management decisions showed a mean sensitivity and specificity of 89.0% (95% CI 87.4% to 90.6%) and 80.7% (95% CI 78.8% to 82.6%). With level II information, the sensitivity significantly improved to 94.1% (95% CI 93.1% to 95.1%; P < 0.001), while the specificity remained unchanged at 80.4% (95% CI 78.4% to 82.4%; P = 0.97). When fixing the CNN's specificity at the mean specificity of the dermatologists' management decision in level II (80.4%), the CNN's sensitivity was almost equal to that of human raters, at 95% (95% CI 83.5% to 98.6%) versus 94.1% (95% CI 93.1% to 95.1%); P = 0.1. In contrast, dermatologists were outperformed by the CNN in their level I management decisions and level I and II diagnostic decisions. More experienced dermatologists frequently surpassed the CNN's performance.

CONCLUSIONS

Under less artificial conditions and in a broader spectrum of diagnoses, the CNN and most dermatologists performed on the same level. Dermatologists are trained to integrate information from a range of sources rendering comparative studies that are solely based on one single case image inadequate.

Nd:YAG and pulsed dye laser therapy in infantile haemangiomas: a retrospective analysis of 271 treated haemangiomas in 149 children

BACKGROUND

Infantile haemangiomas (IH) are common benign tumours in infancy. Most IH resolve spontaneously, but some require treatment due to ulceration, functional impairment or cosmetic disfiguration. While systemic propranolol is effective in many cases, laser therapy may be a safe topical alternative.

OBJECTIVE

To assess the efficacy of combined Nd:YAG/pulsed dye laser (PDL) or PDL alone for therapy of IH.

PATIENTS AND METHODS

A total of 271 IH in 149 infants were treated with combined Nd:YAG/PDL or PDL alone. Based on photographs before and 4-6 weeks after the last treatment, the results were evaluated independently by three physicians. Remissions were categorized as 0-25% (I), 26-50% (II), 51-75% (III) and 76-100% (IV).

RESULTS

In total, 472 laser treatments were performed. In 137 of 149 infants (91.9%) laser therapy was performed during a short sevoflurane mask anaesthesia, while 12 of 149 infants (8.1%) received topical anaesthetic gel. Combined Nd:YAG/PDL was applied in 187 of 271 IH (69.0%), while PDL alone in 84 of 271 IH (31.0%). On average, 1.74 treatments per IH were necessary (Nd:YAG/PDL: 1.95, PDL: 1.26). Moderate or strong (III/IV) improvement was observed in 92.4% of all IH treated. No serious adverse effects were observed.

CONCLUSION

Combined Nd:YAG/PDL therapy is an effective and well-tolerated local treatment option for IH of any classification, in any phase of development and at any age. With regard to the systemic use of propranolol, combined Nd:YAG/PDL therapy seems a safe and promising alternative in many cases.

[Anti-p200/anti-laminin γ1 pemphigoid and BP180 NC16A/4575- positive mucous membrane pemphigoid : late diagnosis in a patient with disease-related loss of vision and multiple previous surgical interventions]

A 87-year-old woman presented with a three-year history of partially erosive, partially bullous skin and mucosal lesions, symblepharon of both eyelids as well as dysphagia. To date, multiple excisions of the skin lesions, which had been described as "skin tumors" by surgeons, had been performed. The synopsis of histology, direct and indirect immunofluorescence established the diagnosis of anti-p200/anti-laminin γ1 pemphigoid and BP180 NC16A/4575- positive mucous membrane pemphigoid with an unusual "epitope-spreading" phenomenon. Due to the late initiation of therapy, the disease-related loss of vision unfortunately was irreversible.

[Giant squamous cell carcinoma of the scalp: successful excision with use of bovine dermal substitute]

A 68-year-old woman presented with an enormous exophytic tumor on her forehead extending to the scalp. After complete resection of the tumor, the resulting defect was closed successfully using a bovine dermal substitute followed by a split-thickness skin graft.

[Phlebology in German departments of dermatology. An analysis on behalf of the German Society of Phlebology]

BACKGROUND

Phlebologic diseases have become extremely common and have major socio-economic impact. However, the percentage of dermatologists working in phlebology appears to be decreasing according to the data of the German Society of Phlebology (DGP).

METHODS

To investigate the reasons for this development, we--on behalf of the DGP--sent a questionnaire to 120 German Departments of Dermatology in autumn 2012.

RESULTS

In 76 returned questionnaires, the number of physicians with additional fellowship training in phlebology averaged 1.5; the average number of those who fulfill the criteria for training fellows in phlebology was 0.9. In 71.1 % of the departments there was a phlebologist. A special phlebologic outpatient clinic existed in 73.7 % of the departments. Sonography with Doppler (89.5 %) and duplex (86.8 %) was used as the most frequent diagnostic tool. For therapy, compression (94.7 %), sclerotherapy (liquid 78.9 %, foam 63.2 %, catheter 18.4 %), endoluminal thermic procedures (radio wave 28.9 %, laser 17.1 %) and surgery (especially crossectomy and stripping 67.1 %, phlebectomy of tributaries 75 %) were used. The average number of treatments was very heterogenous in the different departments.

CONCLUSIONS

Phlebology definitely plays an important role in dermatology. Most departments fulfill the formal criteria for the license to conduct advanced training in phlebology. A wide spectrum of phlebological diagnostic and therapeutic procedures is available.

Thrombophilia in patients with chronic venous leg ulcers-a study on patients with or without post-thrombotic syndrome

BACKGROUND

Chronic venous leg ulcers (CVU) cause considerable burden of disease for the patients as well as enormous costs for health care systems. The pathophysiology of CVU is complex and not entirely understood. So far reliable pathogenic and/or prognostic parameters have not been identified.

OBJECTIVES

We studied the role of thrombophilia in patients referred to a University dermatology department for treatment of CVU.

PATIENTS AND METHODS

A cohort of 310 patients with active chronic venous leg ulcers (CEAP 6) was stratified into two comparably large groups according to the presence or absence of post-thrombotic syndrome (PTS+; PTS-) as determined using duplex scan and/or phlebography. In addition, several thrombophilia parameters were assessed.

RESULTS

The prevalence of protein S deficiency and factor V Leiden mutation was significantly higher in PTS+ patients compared with the PTS- group. However, patients in both subgroups revealed high prevalences of thrombophilia (antithrombin deficiency, protein C deficiency, protein S deficiency, activated protein C resistance, factor V mutation or elevated homocysteine).

CONCLUSION

Based on these data, it is conceivable that thrombophilia contributes to the pathogenesis of CVU, possibly through induction of microcirculatory dysregulations.

Acroangiodermatitis Mali resulting from arteriovenous malformation: report of a case of Stewart-Bluefarb syndrome

We describe the rare Stewart-Bluefarb syndrome in a 15-year-old boy. This syndrome presents as a congenital arteriovenous malformation of the lower leg with multiple arteriovenous shunts accompanied by the benign acroangiodermatitis of Mali (pseudo-Kaposi's sarcoma). The clinical features of this disorder and the treatment options are reviewed.

[Dronabinol for supportive therapy in patients with malignant melanoma and liver metastases]

BACKGROUND

Loss of appetite and nausea can reduce the quality of life of patients with malignant melanoma and liver metastases. Often established antiemetic drugs fail to bring relief. Tetrahydrocannabinol (THC, Marinol), which is the active agent of Indian hemp, has been used successfully in this situation for other malignant tumors.

PATIENTS AND METHODS

We treated 7 patients with hematogenous metastatic melanoma and liver metastases suffering from extensive loss of appetite and nausea supportively with dronabinol (Marinol. All of these patients had previously received standard antiemetic therapy without adequate relief. Dronabinol is a synthetic Delta-tetrahydrocannabinol. The drug was administered in capsule form. We evaluated the palliative effects of dronabinol with a special patient evaluation form, which was filled out at the beginning of the therapy and again after 4 weeks.

RESULTS

The majority of patients described a significant increase in appetite and decrease in nausea. These effects remained for some weeks, but then decreased as metastases progressed and the general condition worsened. All of the patients experienced slight to moderate dizziness, but it was not sufficiently troubling to cause interruption or termination of therapy.

CONCLUSION

Loss of appetite and nausea due to liver metastases of malignant melanoma can be treated in individual cases supportively with Dronabinol.

Extracorporeal photochemotherapy for the treatment of exanthematic pityriasis rubra pilaris

Pityriasis rubra pilaris (PRP) is a rare papulosquamous skin disease of unknown aetiology that has been categorized into five clinical types based on age at onset, cutaneous features and prognosis. We present a patient with chronic exanthematic type II atypical adult PRP, whose skin status was significantly improved with monthly extracorporeal photochemotherapy (ECP). Various therapeutic regimens including narrow-band UV-B, bath PUVA therapy, systemic fumaric acid esters and systemic cyclosporin had failed. Oral retinoids could not be administered due to a type IIa hyperlipoproteinemia with profound hepatic steatosis and elevated liver transaminases. The observed clinical benefit may encourage future clinical studies analysing the effectiveness of ECP in otherwise unresponsive cases of type II PRP.

Schimmelpenning-Feuerstein-Mims syndrome with hypophosphatemic rickets

The Schimmelpenning-Feuerstein-Mims syndrome (SFM syndrome) is a rare and variable multisystem defect consisting of congenital, extensive linear nevus sebaceus and associated abnormalities in different neuroectodermal organ systems. We present the history of a 52-year-old female patient with disproportionate hyposomia and asymmetric constitution. From birth she suffered from a right-sided, extensive nevus sebaceus following Blaschko's lines extending on the scalp, neck, right arm and trunk. At the age of 5 years, she developed a generalized growth retardation, along with deformations of bones. At the age of 11, hypophosphatemic rickets was diagnosed causing this growth retardation. Moreover, the patient developed a precocious puberty at the age of 9 years. When we saw the patient 40 years after the diagnosis had been made, phosphaturia had returned to normal. Specific therapy of hypophosphatemic rickets is straightforward and efficient in preventing late complications like growth retardation. We suggest to conduct appropriate laboratory tests in early childhood in patients with an extensive systematized sebaceous nevus or with additional signs of growth retardation or skeletal involvement, in order to exclude hypophosphatemic rickets associated with SFM syndrome.

Inefficacy of vindesine monotherapy in advanced stage IV malignant melanoma patients previously treated with other chemotherapeutic agents

The anti-melanoma activity of vindesine as a single or polychemotherapeutic agent has been reported previously in adjuvant and first-line melanoma treatment. In this study, we investigated the usefulness of vindesine monotherapy as salvage therapy in stage IV melanoma patients after failure of other chemotherapies. Thirteen patients with progressive disease were treated with 3 mg/m2 vindesine every 2 weeks (median age, 61 years). Previous systemic treatment consisted of polychemotherapy or combined chemo-immunotherapy. All 13 patients suffered from visceral metastases (three lung, one liver, one adrenal gland and eight multiple visceral metastases). A median of three vindesine treatments was administered. Despite the various pre-treatments, the toxicity of vindesine was mild. In all 13 patients, vindesine treatment was stopped due to disease progression. The median survival after primary tumour diagnosis was 42 months (8-151 months), the survival after entering stage IV was 11 months (3-35 months), and the survival after starting vindesine therapy was 4 months (1-22 months). We conclude that vindesine monotherapy is ineffective in stage IV melanoma patients previously treated with other chemotherapeutic agents.

[Improved scar formation after using a medical surgical zipper for wound closure under tension]

BACKGROUND AND OBJECTIVE

The objective of the study was to evaluate the use of a medical surgical zipper (Medizip) for wound closure under tension in comparison to conventional cutaneous sutures. The surgical zipper is supposed to reduce wound tension by approximating of the wound edges via epidermal traction.

PATIENTS/METHODS

This prospective study included patients with a wound diameter of more than 1 cm. 45 patients were treated with the surgical zipper, 38 were randomized into a control group with conventional wound closure. Scars were assessed after 6-18 months focusing on aesthetic and functional aspects.

RESULTS

The average length of the scars in both groups was 9 cm, but after a observation time of at least 6 month, there were differences in the width of the scars. The group with the surgical zipper showed significantly thinner scars (2.74 mm versus 4.24 mm, p=0.0008). Only 17% of the Medizip patients developed unaesthetic rope ladder-like scars versus 65% in the control group. This observation was statistically significant (p<0.0001).

CONCLUSIONS

Wound stabilization by approximation of the wound edges via surgical zipper results in improved scar formation in wounds with moderate tension. Using the Medizip trade mark in wounds under heavy tension is not recommended because of the possible development of to tension bullae under the zipper.

Operative Sanierung florider venöser Ulzera

Ziel: Die vorliegende Qualitätssicherungsstudie soll die Häufigkeit von Wundinfekten nach operativen Eingriffen wegen floridem Ulcus cruris venosum an der Abteilung Dermatologie der Universität Göttingen erfassen. Außerdem wird die präoperative Besiedlung der stationär vorbehandelten Ulzera mit pathogenen Mikroorganismen dargestellt. Methoden: 59 Patienten mit Ulcus cruris venosum wurden 95 operativen Eingriffen unterzogen (46-mal einseitig, 13-mal beidseitig; insgesamt 75 Operationen am oberflächlichen Venensystem und 20 paratibiale Fasziotomien). Allen Patienten wurde eine am präoperativen Antibiogramm orientierte perioperative antibiotische Prophylaxe (PAP) als Einmalgabe verabreicht. Ergebnisse: Präoperativ wurde auf den Ulzera am häufigsten eine Besiedlung durch Staphylococcus aureus, gefolgt von Proteus mirabilis, nachgewiesen. In 3 Fällen (5,1%) wurden Methicillin-resistente Staphylokokken gefunden. Cefazolin und Ciprofloxacin waren die häufigsten zur PAP verabreichten Antibiotika. Insgesamt beobachteten wir bei 5 von 59 Patienten (8,5%) postoperative Wundinfekte, in 3 Fällen waren die präoperativ nachgewiesenen pathogenen Keime Ursache der Wundinfektion. Schlussfolgerung: Der Prozentsatz postoperativer Wundinfekte nach Sanierung venöser Ulzera unter dem Schutz einer am präoperativen Antibiogramm orientierten PAP ist mit 8,5% vertretbar.

Dynamic lymphoscintigraphy and image fusion of SPECT and pelvic CT-scans allow mapping of aberrant pelvic sentinel lymph nodes in malignant melanoma

To date, there are no reliable criteria to identify those patients with melanoma-infiltrated sentinel lymph nodes (SLNs) of the groin who might benefit from an extended lymphadenectomy, including the pelvic lymph nodes. We hypothesised that there are pelvic lymph nodes that receive lymph directly from the primary tumour, thus being at an increased risk for metastasis. In order to determine the frequency of radioactively labelled pelvic lymph nodes and the kinetics of their appearance, we introduce here a combination of dynamic lymphoscintigraphy, single photon emission computed tomography (SPECT) and image fusion of SPECT and pelvic Computed Tomography (CT)-scans. By dynamic lymphoscintigraphy and intraoperative gamma probe detection, superficially located inguinal SLNs (median 2 nodes) could be identified in all of the 51 patients included in this analysis. The histological search for micrometastases was positive in 16 patients (median Breslow thickness of the primary melanoma 2.5 mm). In 29 patients, SPECT and the image fusion technique were additionally performed. Radioactively labelled pelvic lymph nodes were detected in 20 individuals, 6 of them presenting aberrant pelvic SLNs that, on dynamic lymphoscintigraphy, had appeared simultaneously with the superficial SLN(s). Of the 6 patients in whom radioactive pelvic lymph nodes were excised together with the superficial SLN(s), only one had positive superficial SLNs. In this patient, the aberrant pelvic SLN proved to be tumour-positive. In 9 patients, there was no radiotracer uptake in the pelvic lymph nodes at all. Image fusion of SPECT and pelvic CT-scans is an excellent tool to localise exactly the pelvic tumour-draining nodes. The significance of radioactively labelled pelvic lymph nodes for the probability of pelvic metastases should be analysed further.

Idiopathische Calcinosis cutis mit ausgedehnten Unterschenkelulzera

Es wird über eine 51-jährige Patientin mit einer idiopathischen Calcinosis cutis berichtet. Die Krankheit manifestierte sich als chronische, stark schmerzhafte, bizarr konfigurierte und therapieresistente Ulcera crurum beidseits. Die umgebende Haut zeigte blitzfigurenartige Gefäßzeichnungen im Sinne einer Livedo racemosa. Histologisch ließ sich in der mittleren und tiefen Dermis eine okkludierende Vaskulopathie der mittelgroßen und kleinen Gefäße mit massiven Intimaverkalkungen, weiterhin Verkalkungen ohne Gefäßassoziationen in der Subkutis nachweisen. Radiologisch kamen ausgedehnte Weichteilverkalkungen der Unterschenkel zur Darstellung. Pathogenetisch kommt es zur Ablagerung von Kalziumphosphat und Kalziumkarbonat in Gefäßwänden und im Haut-/Weichteilgewebe mit konsekutiver Nekrose. Grunderkrankungen, die zu einer Calcinosis cutis führen können, wurden bei unserer Patientin bisher nicht gefunden. Wir führten trotz eines nur grenzwertig erhöhten Serumphosphatspiegels eine orale Behandlung mit dem Phosphatsenker Aluminiumchloridhydroxid- Komplex durch. Die Therapie wurde sehr gut vertragen. Es kam bereits nach wenigen Wochen zur guten Wundgrundgranulation, verbunden mit einer signifikanten Besserung der Schmerzsymptomatik. Die Ulzera heilten nach Spalthautdeckung komplikationslos ab. Der vorliegende Fall bestätigt die bereits in Einzelkasuistiken berichtete Wirksamkeit von phosphatsenkenden Medikamenten zur Behandlung der Calcinosis cutis.

[Increased serum alpha 1-antitrypsin does not produce a rise in fecal alpha 1-antitrypsin in patients with healthy intestines]

Fecal alpha-1-Antitrypsin (alpha-1-AT) was related to serum alpha-1-AT concentration in 50 healthy controls, 51 patients with extraintestinal inflammatory disease as well as in 23 patients with ulcerative colitis with mild or severe disease activity. alpha-1-AT concentrations were measured by radial immunodiffusion. Even though serum alpha-1-AT concentration was elevated above normal limits in all patients, a concomitant increase of fecal alpha-1-AT was found only in patients with ulcerative colitis. In these patients a positive correlation between fecal alpha-1-AT-clearance and -concentration and severity and extension of inflammation could be demonstrated. It is concluded that elevated blood levels of alpha-1-AT do not cause increases in fecal alpha-1-AT loss and that fecal alpha-1-AT excretion is increased specifically in patients with intestinal inflammation.