This transcript details the microscopic examination of an excised skin lesion characterized by a large nodule extending through the dermis into the subcutis. The macroscopic appearance of the lesion includes pink and grayish/grayish-blue coloration, attributed to an infiltrate composed of cells rather than just collagen. On closer examination, the cells possess abundant cytoplasm which appears foamy or bubbly, making it difficult to visualize clearly on a digital scan compared to traditional light microscopy where condenser adjustments would reveal this refractive quality. The presence of abundant pale cytoplasm in dermal infiltrating cells, resulting in a grayish-pink color at low power, strongly suggests the presence of histiocytes. Given the large nodule structure composed of foamy histiocytes, the diagnosis is identified as a tuberous xanthoma, which is typically associated with abnormal serum lipids, necessitating lipid panel testing for the patient.
Analysis of Excised Skin Lesion: Tuberous Xanthoma
00:00:10 Lesion Characteristics: The excised lesion is a large nodule filling the dermis and extending into the subcutis, showing pink coloration along with grayish/grayish-blue areas.
00:00:29 Cellular Infiltrate: The grayish color is due to an infiltrate composed of a "sheet of cells," not just collagen.
00:00:44 Cell Morphology: The constituent cells have abundant round/oval nuclei and abundant, foamy/bubbly cytoplasm.
00:00:50 Visualization Difficulty: Foamy cytoplasm is hard to see well on digital scans because it is refractile; this feature is better seen with condenser adjustments on a light microscope.
00:01:10 Histiocyte Suggestion: The presence of abundant pale cytoplasm in dermal infiltrating cells, causing a grayish-pink color at low power, suggests the presence of histiocytes.
00:01:33 Diagnosis: A large nodule made of foamy histiocytes is diagnosed as a tuberous xanthoma.
00:01:41 Clinical Relevance: Tuberous xanthomas are usually associated with abnormal serum lipids, making it important to check the patient's serum lipid panel if they don't already have a dyslipidemia diagnosis.