Lessons in clinical reasoning - pitfalls, myths, and pearls: shoulder pain as the first and only manifestation of lung cancer.

OBJECTIVES: Lung cancer is the leading cause of cancer-related death and poses significant challenges in diagnosis and management. Although muscle metastases are exceedingly rare and typically not the initial clinical manifestation of neoplastic processes, their recognition is crucial for optimal patient care. CASE PRESENTATION: We present a case report in which we identify the unique scenario of a 60-year-old man with shoulder pain and a deltoid muscle mass, initially suggestive of an undifferentiated pleomorphic sarcoma. However, further investigations, including radiological findings and muscle biopsy, revealed an unexpected primary lung adenocarcinoma. We performed a systematic literature search to identify the incidence of SMM and reflect on how to improve and build on better diagnosis for entities as atypical as this. This atypical presentation highlights the importance of recognizing and addressing cognitive biases in clinical decision-making, as acknowledging the possibility of uncommon presentations is vital. By embracing a comprehensive approach that combines imaging studies with histopathological confirmation, healthcare providers can ensure accurate prognoses and appropriate management strategies, ultimately improving patient outcomes. CONCLUSIONS: This case serves as a reminder of the need to remain vigilant, open-minded, and aware of cognitive biases when confronted with uncommon clinical presentations, emphasizing the significance of early recognition and prompt evaluation in achieving optimal patient care.

Fenómeno de vacío en la bursa iliopsoas como posible fuente de error diagnóstico radiológico / Vacuum phenomena in iliopsoas bursa: a possible pitfall at CT and MR imaging

El fenómeno de vacío es una alteración conocida en las articulaciones osteoartríticas. En ocasiones puede verse gas en las bursas adyacentes a las articulaciones debido a la existencia de una comunicación con la articulación. Presentamos un caso de fenómeno de vacío en la bursa iliopsoas en asociación a una cadera osteoartrítica sobre la base de una displasia acetabular en una mujer de 48 años que acudió a nuestra consulta con sospecha inicial de absceso de iliopsoas.

Vacuum phenomena is a well-known alteration in osteoarthritis. It´s possible to see gas in bursas around osteoarthritic joints due to comunication between them. We describe an unusual case of vacuum phenomena arising within an enlarged iliopsoas bursa in association with mildly osteoarthritic and dysplastic hip in a 48-year-old woman who underwent radiologic study in our institution with an initial suspiction of iliopsoas abscess.

[Lipoma arborescens of the bicipital bursa]. / Lipoma arborescente de la bursa bicipital.

Lipoma arborescens is a rare benign entity characterized by proliferation of villous fat tissue in subsynovial layer that usually affects the knee joint. We report a case of lipoma arborescens in bicipitoradial bursa of the elbow in a 44 year-old female patient. In spite of this rare location, radiographic findings by ultrasonography and magnetic resonance imaging made diagnosis possible.

Growth hormone does not alter CYP2A6 activity in growth hormone-deficient children.

A large number of metabolic alterations are increasingly being treated with growth hormone. Despite the fact that growth hormone is known to be the main regulator of several hepatic drug metabolizing enzymes in rodents, few studies deal with the effect of growth hormone on hepatic enzyme activities in human beings. The aim of this study was to determine the effects of growth hormone replacement therapy for 4 weeks on CYP2A6 activity in children, because changes in this enzyme activity may have important therapeutic and toxic consequences. A total of 31 growth hormone-deficient children (age range 4.1-13.1 years; mean age 9.88 +/- 2.89 years) participated. The genotypes of CYP2A6 gene, CYP2A6*1A, CYP2A6*1B, CYP2A6*4, CYP2A6*1x2 and CYP2A6*9, were determined by polymerase chain reaction. To assess the enzyme activity, we used caffeine as a probe drug at two points in time: before starting growth hormone therapy (Day 0) and after 4 weeks of growth hormone therapy (Day A). Caffeine and metabolite concentrations in urine were assayed by high-pressure liquid chromatography. The metabolite ratio 1,7-dimethilxanthine to 1,7-dimethylurate (17U/17X) served to indicate CYP2A6 activity. Median value and 95% confidence interval at baseline was 1.08 (0.98-1.24). The value after treatment was 1.08 (0.86-1.21). Data comparison between periods showed lack of statistically significant differences (P > 0.05). The relative change, measured by the ratio of medians and 90% confidence interval, was 1.02 (0.84-1.19). There were no significant differences when the ratio between genotype groups were compared. These results indicate that growth hormone replacement therapy of growth hormone-deficient children for 4 weeks does not modify the CYP2A6 activity and hence the efficacy or toxicity of the CYP2A6 substrate compounds.