Trichoblastoma is a rare, slow-growing, benign cutaneous tumor derived from follicular germinative cells. Trichoblastoma commonly appears as an asymptomatic, symmetrical, well-circumscribed, skin-colored to brown or blue-black papule or nodule. It may appear clinically and histologically similar to basal cell carcinoma, making its diagnosis challenging. Even on dermoscopy, it is challenging to differentiate trichoblastoma from basal cell carcinoma. In practice, it is important to differentiate the two, because the choice of treatment and resulting prognosis differ between the lesions. Surgical biopsy to analyze histopathological and immunohistochemical differences is the gold standard for diagnosing and differentiating trichoblastoma from basal cell carcinoma. Trichoblastoma typically has a favorable prognosis, with a low incidence of recurrence, progression or association with malignancy. This paper provides a review of the epidemiology, clinical presentation, dermoscopy, histology, immunochemistry, treatment, and prognosis of trichoblastoma.

BackgroundAlthough the natural history of vestibular schwannomas (VS) has been previously studied, few studies have investigated associated epidemiological factors, primarily because of the lack of large available cohorts.ObjectiveThe objective of this study was to perform a multi-scale geographical analysis of the period prevalence of VS in West Scotland from 2000 to 2015.MethodsAdults diagnosed with sporadic VS were identified through the National Health Services of West Scotland database and geocoded to the unit postcode. To assess whether the cohort of VS cases could be pooled into a period prevalence measure, the locations of VS cases were analyzed by sex using Cross-L and Difference-K functions. VS period prevalence was examined at two aggregate spatial scales: the postcode district and a coarser scale of NHS Health Boards. The spatial structure of period prevalence within each level of spatial aggregation was measured using univariate global and local Moran’s I. Bivariate local Moran’s I was used to examine the between-scale variability in period prevalence from the postcode district level to the NHS Health Boards levels. Prior to spatial autocorrelation analyses, the period prevalence at the postcode district was tested for stratified spatial heterogeneity within the NHS Health Boards using Wang’s q-Statistic.ResultsA total of 512 sporadic VS were identified in a population of over 3.1 million. Between 2000 and 2015, VS period prevalence was highest within the NHS Health Boards of Greater Glasgow and Clyde, Ayrshire and Arran and the Western Isles. However, at the NHS scale, period prevalence exhibited no spatial autocorrelation globally or locally. At the district scale, Highland exhibited the most unusual local spatial autocorrelation. Bivariate local Moran’s I results indicated general stability of period prevalence across the postcode district to Health Boards scales. However, locally, some postcode districts in Greater Glasgow and Clyde, Ayrshire and Arran exhibited unusually low district to zone spatial autocorrelation in period prevalence, as did the southern parts of the Western Isles. Some unusually high period prevalence values between the postcode district to Health Board scale were found in Tayside, Forth Valley and Dumfries and Galloway.ConclusionGeographic variability in VS in West Scotland was identified in this patient population, showing that there are areas, even remote, with unusually high or low period prevalence. This can be partially attributed to links between primary and tertiary care. Potential genetic or environmental risk factors that may contribute to geographic variation in this disease within Scotland are also a possibility but require further investigation.

Rationale: Hypokalemia is a common finding. Typically asymptomatic presentations of neuromuscular weakness emerge at levels below 2.5 mmol/L. Causes include gastrointestinal losses, renal losses, or intracellular shift, with gastrointestinal losses and diuretics accounting for the majority. Although the cause is often apparent on clinical assessment, a systematic approach incorporating urine biochemistry can aid in narrowing the differential in obscure cases. Presentation: We describe a case of a previously healthy 27-year-old man who presented with acute ascending paralysis, with an associated severe hypokalemia and metabolic acidosis. There were no apparent causes on clinical assessment. Diagnosis: Based on analysis of urine biochemistry, we concluded that a pathologic kaluresis was present, and given his acidemia and transient pathology, we diagnosed the patient with hypokalemic paralysis secondary to toluene toxicity. Interventions: We provided supportive care and electrolyte repletion for our patient; no specific therapies for toluene were required. Our patient was counseled regarding appropriate protective measures when handling toluene. Outcomes: Complete neurologic recovery and biochemical normalization occurred within 48 hours of presentation with supportive care. He continued to use proper precautions when handling toluene, and experienced no symptom relapse, or further abnormalities on both blood and urine chemistry. Lessons learned: Using this case, we review an algorithmic approach incorporating urine biochemistries to aid in the workup of hypokalemia. We review toluene as a toxicologic entity and highlight its role as a cause of hypokalemia.

Background: Laryngeal chondrosarcomas are rare, slow-growing, cartilaginous tumors. Dedifferentiated chondrosarcomas, a rare entity of chondrosarcoma, are more aggressive and associated with a more ominous prognosis. Definite diagnosis can be established by incisional biopsy and histopathologic examination. Histopathologic examination reveals a cartilaginous tumor with a malignant spindle cell component. Definitive reatment of dedifferentiated chondrosarcomas of the larynx is total laryngectomy. There have been 14 case reports of laryngeal dedifferentiated chondrosarcoma reported since 1988. The average life expectancy reported is 6 months, and a 5-year survival rate of 10.5%. Case presentation:We present a case of dedifferentiated chondrosarcoma arising in the cricoids cartilage of a male patient, who presented with 3-week history of dyspnea, stridor, dysphonia and intermittent aphonia. As a result, he underwent a total laryngectomy, and received adjuvant radiation therapy. Conclusion:Laryngeal dedifferentiated chondrosarcoma is a rare entity. Symptoms include dyspnea, hoarseness, dysphagia, and a painless neck mass. Due to the aggressiveness of the tumor, it is essential to include it as a differential diagnosis among the other laryngeal tumors.

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