[Cutaneous pseudolymphoma after hirudotherapy : Case report and review]. / Kutane Pseudolymphome nach Hirudotherapie : Fallbericht und Literaturübersicht.

The term cutaneous pseudolymphoma (C-PSL) is defined in the literature as a benign, reactive lymphoproliferation that clinically and/or histopathologically imitates cutaneous lymphoma. The exact etiopathogenesis has not been fully elucidated to date. A distinction is made between primary, idiopathic PSL without an identifiable cause and secondary PSL with a known stimulus. We report the occurrence of pseudolymphoma after treatment with medicinal leeches (hirudotherapy). To the best of our knowledge, a total of only nine cases of cutaneous PSL after hirudotherapy have been reported in the literature to date.

Furuncular Myiasis of the Lower Leg.

A 35-year-old Caucasian woman, otherwise healthy, presented with a four weeks history of painful, inflammatory nodules, each with a central opening on her right lower leg (Figure 1). Intermittently, a marked serosanguinous secretion was noted. The remaining skin and mucosa were not affected. The patient denied any history of trauma. One month earlier she had returned from a journey to Peru. Despite topical treatment with corticosteroids and antibiotics as well as systemic therapy with oral doxycycline, the lesions did not show any regression or reduction in their secretion. An incisional biopsy was performed at all sites and the extracted organic specimens were submitted for histopathological assessment. Histopathology revealed a mixed inflammatory dermal infiltrate consisting of numerous eosinophils admixed with some histiocytes and lymphocytes. Furthermore, an organic foreign body with an eosinophilic cuticle consistent with DH became evident (Figure 2, a-e). Human myiasis represents the infestation of humans by developing dipterous larvae (maggots) of various fly species (1). The most common flies causing human myiasis are Dermatobia hominis (DH, "human botfly") and, less frequently, Cordylobia anthropophaga ("tumbu fly") or Cordylobia rodhaini (1). DH is indigenous in Central and South America, but in Europe and the United States of America only cases of travelers that imported the infestation have been described (2,3). The adult DH is a yellow-headed fly with a grey-blue body of approximately 15 mm. DH is active throughout the year and predominantly found in humid and high temperature regions of Central and South America (2). The larvae of DH develop as obligate parasites in living tissue, causing furuncular myiasis (2,4). Clinically crusted nodules with serosanguinous secretion and sometimes nocturnal pain affecting uncovered anatomical sites are typical (2,4). Differential diagnoses include bacterial furunculosis, arthropod bite reaction, pyoderma, inflamed epidermoid cysts, or cutaneous leishmaniasis (2,5-7). Most cases of furuncular myiasis can be diagnosed solely by their clinical presentation and after carefully taking the patients' history. Nevertheless, dermoscopy and sonography may help to confirm the diagnosis and rule out the abovementioned differential diagnoses (6,7). Although myiasis is a self-limited disease, it can be accompanied by severe complications including tetanus or bacterial superinfections (2). The literature reports a number of treatment options including a) occlusion of the skin opening by paraffin oil, beeswax, petroleum jelly or agents such as liquid nitrogen or ethyl chloride sprays to suffocate the larva and promote self-extrusion; b) removing the larva by forceps after lidocaine instillation; c) surgical removal or d) the use of topical or oral ivermectin (1,8,9). Preventive measures include protective clothing, insect repellents, and sleeping curtains. Histopathology of furuncular myiasis typically reveals a mixed inflammatory infiltrate of eosinophils, lymphocytes, and macrophages. Sometimes formation of granulomas with giant cells becomes evident (10). Fly larvae show a thick eosinophilic cuticle with external facing sclerotized spines. Internal structures (respiratory and digestive tracts or striated muscle) may occasionally be identified (10), (Figure 2, b-e). In most cases, tissue sections will not be sufficient to identify the fly's genus or its species; however, identification by stereomicroscopy has been reported (10). In conclusion, we described the clinical and histopathological features of furuncular myiasis by DH in a traveler returning from Peru. Given the ever-increasing numbers of international travelers, western dermatopathologists and dermatologists should be familiar with this disease to avoid prescription of unnecessary topical or systemic medications.

Man against machine: diagnostic performance of a deep learning convolutional neural network for dermoscopic melanoma recognition in comparison to 58 dermatologists.

Background: Deep learning convolutional neural networks (CNN) may facilitate melanoma detection, but data comparing a CNN's diagnostic performance to larger groups of dermatologists are lacking. Methods: Google's Inception v4 CNN architecture was trained and validated using dermoscopic images and corresponding diagnoses. In a comparative cross-sectional reader study a 100-image test-set was used (level-I: dermoscopy only; level-II: dermoscopy plus clinical information and images). Main outcome measures were sensitivity, specificity and area under the curve (AUC) of receiver operating characteristics (ROC) for diagnostic classification (dichotomous) of lesions by the CNN versus an international group of 58 dermatologists during level-I or -II of the reader study. Secondary end points included the dermatologists' diagnostic performance in their management decisions and differences in the diagnostic performance of dermatologists during level-I and -II of the reader study. Additionally, the CNN's performance was compared with the top-five algorithms of the 2016 International Symposium on Biomedical Imaging (ISBI) challenge. Results: In level-I dermatologists achieved a mean (±standard deviation) sensitivity and specificity for lesion classification of 86.6% (±9.3%) and 71.3% (±11.2%), respectively. More clinical information (level-II) improved the sensitivity to 88.9% (±9.6%, P = 0.19) and specificity to 75.7% (±11.7%, P < 0.05). The CNN ROC curve revealed a higher specificity of 82.5% when compared with dermatologists in level-I (71.3%, P < 0.01) and level-II (75.7%, P < 0.01) at their sensitivities of 86.6% and 88.9%, respectively. The CNN ROC AUC was greater than the mean ROC area of dermatologists (0.86 versus 0.79, P < 0.01). The CNN scored results close to the top three algorithms of the ISBI 2016 challenge. Conclusions: For the first time we compared a CNN's diagnostic performance with a large international group of 58 dermatologists, including 30 experts. Most dermatologists were outperformed by the CNN. Irrespective of any physicians' experience, they may benefit from assistance by a CNN's image classification. Clinical trial number: This study was registered at the German Clinical Trial Register (DRKS-Study-ID: DRKS00013570; https://www.drks.de/drks_web/).

Increased HCN channel driven inward rectification in benign cramp fasciculation syndrome.

Muscle cramps are a common complaint associated with sudden painful involuntary contractions of a muscle. The mechanisms responsible for muscle cramps are still not clear. Axonal excitability and multi-unit electromyography studies were performed in 20 patients suffering from benign cramp fasciculation syndrome, not currently on medication. The measures of axonal excitability suggested greater inward rectification, indicative of an increase in Ih. Mathematical modelling suggested that the data were best explained by depolarization of the voltage dependence of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. Parameters associated with polarization of resting membrane potential were not changed. These findings suggest that a role for HCN channels may become apparent during the rhythmic discharge associated with a voluntary contraction. Consistent with this view, patients had higher motor unit discharge rates than healthy controls during maximal voluntary effort.