An infant is born with a 7 cm × 6 cm lesion over the upper extremity from the elbow to the shoulder. The lesion is indurated and purpuric, with some petechiae around the edges. No other areas of petechiae are noted on the skin. The infant is doing well without other systemic problems. i were 9 and 9. You are called by the pediatric nurse practitioner to the NICU. What is the most appropriate next step?

Correct Answer: D

Rationale: The correct answer is D: Obtain labs, including a CBC with platelet count and fibrinogen. This is the most appropriate next step because the infant's presentation with an indurated and purpuric lesion raises concern for a possible bleeding disorder or coagulopathy. By obtaining labs, including a CBC with platelet count and fibrinogen, we can assess the infant's hemostatic profile and rule out any underlying hematologic abnormalities. This step is crucial in ensuring the infant's well-being and guiding further management if any abnormalities are detected. Why the other choices are incorrect: A: Doing nothing is not appropriate as the presentation warrants further investigation. B: An ultrasound may not provide useful information in this scenario as the lesion is concerning for a systemic issue. C: An MRI is not the initial diagnostic test of choice for evaluating a possible bleeding disorder or coagulopathy.

Correct Answer: B

Rationale: The correct answer is B because autologous hematopoietic stem cell transplantation should be used when it can provide a survival benefit over chemotherapy. This approach is particularly beneficial for certain cancers such as neuroblastoma and relapsed lymphoma. - Choice A is incorrect because the indication for autologous transplantation is not solely based on the need for high-dose therapy, but rather on providing a meaningful survival benefit over chemotherapy. The listed cancers are not the most common ones treated with this approach. - Choice C is incorrect because the graft-versus-tumor effect is actually desired in some cases of autologous transplantation, and the listed cancers are not the most common ones treated with this approach. - Choice D is incorrect because the purpose of autologous transplantation is not to avoid extensive chemotherapy but to provide a survival benefit. The listed cancers are not the most common ones treated with this approach.

Correct Answer: B

Rationale: The correct answer is B: Leukocyte adhesion deficiency (LAD) Type II. This patient's symptoms of recurrent bacterial infections, leukocytosis, neutrophilia, short stature, and Bombay blood group (lack of H antigen) are characteristic of LAD Type II. In LAD Type II, there is a defect in fucose metabolism, leading to impaired leukocyte adhesion and migration, causing immune dysfunction. Chediak-Higashi syndrome (A) presents with oculocutaneous albinism, recurrent infections, and giant granules in leukocytes. CD18 deficiency (C) is a type of LAD characterized by mutations in the CD18 gene causing impaired integrin function. Griscelli syndrome (D) presents with silvery hair, immunodeficiency, and neurological deficits, not matching this patient's symptoms.

Correct Answer: C

Rationale: The correct answer is C: T-cell numbers in infants are higher than in adults. This is because infants have a relatively higher proportion of T-cells compared to adults due to their underdeveloped immune system. T-cell numbers decrease with age as the immune system matures and adapts to the environment. Rationale: 1. T-cells play a crucial role in the immune response, especially in infants who rely heavily on cellular immunity. 2. NK-cell numbers do not follow the pattern described in option A, as they are important in early immune responses. 3. B-cell numbers do not decline with age as stated in option B, as they are responsible for antibody production throughout life. 4. Option D is incorrect as infants actually have higher lymphocyte counts compared to adults due to their developing immune system.

Correct Answer: D

Rationale: The correct answer is D because the patient has residual lung nodules after initial chemotherapy, indicating a need for intensified treatment. Adding cyclophosphamide and etoposide to the chemotherapy regimen can improve outcomes in patients with combined loss of heterozygosity for 1p and 16q. Radiation to both the lungs and flank targets all remaining disease sites effectively. Choice A is incorrect because it does not address the need for intensified treatment with additional agents or radiation to the lungs, where residual disease remains. Choice B is incorrect as it only includes radiation to the flank and not the lungs, which are still harboring disease. Choice C is incorrect because although it adds cyclophosphamide and etoposide, it does not include radiation to the lungs, which is necessary for comprehensive disease control.