One complication of deep vein thrombosis (DVT) is:

A. Basal cell carcinoma is incorrect because it is the most common type of skin cancer but is generally slow-growing and rarely metastasizes. It primarily causes local tissue damage if untreated but has a very low risk of spreading to distant sites.

B. Melanoma is correct because melanoma is a malignant tumor of melanocytes and is highly aggressive. If not detected and treated early, melanoma can metastasize to lymph nodes and distant organs, including the liver, lungs, and brain. Early detection and surgical excision are critical to prevent spread and improve survival. Risk factors include excessive UV exposure, fair skin, a history of sunburns, and multiple moles.

C. Squamous cell carcinoma is incorrect because although it is malignant and can invade surrounding tissues, squamous cell carcinoma has a lower tendency to metastasize than melanoma. However, untreated lesions can become locally destructive and, in rare cases, metastasize to regional lymph nodes.

D. Actinic keratosis is incorrect because it is a precancerous lesion, not a true cancer. These rough, scaly patches result from chronic sun exposure and have the potential to progress to squamous cell carcinoma over time, but they are not inherently malignant or metastatic.

A. Burn to left leg is incorrect because a localized burn to an extremity indicates direct thermal injury to the skin at that site, not smoke inhalation. Smoke inhalation injuries primarily affect the airways and lungs rather than isolated skin areas.

B. Wheezing is correct because wheezing indicates airway obstruction or irritation caused by inhaled smoke, heat, or chemical particles. This can result from bronchospasm, edema, or inflammation of the respiratory tract.

C. Singed nose hairs is correct because singed nasal hairs are an early external sign of inhalation of hot gases or smoke, suggesting that the upper airway has been exposed to heat and possibly chemical irritants.

D. Black-tinged sputum is correct because the presence of soot in the sputum indicates that smoke particles have been inhaled and deposited in the respiratory tract, confirming inhalation injury.

E. Difficulty breathing is correct because respiratory distress can occur due to airway edema, chemical irritation, or inhaled toxins from the fire. Difficulty breathing may range from mild dyspnea to severe respiratory compromise, requiring immediate assessment and intervention.