To Transplant or Not to Transplant? Late-Onset Primary HLH in a Patient: A Case Report and Review of Literature.

Primary, or familial, hemophagocytic lymphohistiocytosis (P-HLH) is a rare inherited autosomal-recessive immune deficiency which generally manifests during infancy or early childhood. Recent literature suggests an increased number of reports of late-onset P-HLH, especially in association with infection and underlying malignancy. The authors describe a case of subcutaneous T-cell lymphoma in a 8-year-old child that was complicated by primary, perforin-deficient HLH. In contrast, we examined retrospective data for 19 cases of late-onset P-HLH with available treatment data and compared the results of conservative medical therapy with hematopoietic stem cell transplant (HSCT) postremission therapy. Our patient displayed compound heterozygous mutations in PRF1 that have not been described in the literature previously: allele 1 [c.786_801del(p.Gln263fs)] and allele 2 [c.886T>C(p.Tyr296His)]. Of the 19 cases analyzed, 14 achieved remission. Postremission, 7 of 14 (50%) received HSCT and were reported alive at a median time of 24 months, 5 of 14 (36%) received medical therapy and were reported alive at a median time of 24 months, and 2 of 14 (14%) received medical therapy and died at a median of 73 months postremission. Our retrospective literature review suggests that some patients can survive late-onset, perforin-deficient, P-HLH without the potential lifelong risks of HSCT when in the first remission.

Effective Use of Sirolimus and Zoledronic Acid for Multiosteotic Pseudomyogenic Hemangioendothelioma of the Bone in a Child: Case Report and Review of Literature.

Pseudomyogenic hemangioendothelioma (PMH) is a rare neoplasm with vascular and sarcomatous elements, unpredictable course, and uncommon metastatic or fatal potential. Although systemic chemotherapy has been reported with variable success, generally accepted treatment is aggressive surgery with wide margins. Evidence-based treatment options are lacking, and lack of clear prognostic features poses a risk of undertreatment or overtreatment with associated morbidity and mortality. We report the use of initial systemic therapy with oral sirolimus (SIR) and IV zoledronic acid (ZA) to induce a sustained clinical response and avoidance of amputation in a 6-year-old boy. At 37 months after diagnosis, our patient remains in sustained clinical remission as documented by x-ray, MRI, and PET-CT with return of normal mobility/activity and resolution of swelling and pain. Literature review identified 20 cases of pediatric and young adult patients with PMH, of which 7 received some form of systemic therapy. To the best of our knowledge, our patient represents the youngest reported case of PMH and the first successful and limb-sparing utilization of systemic chemotherapy as primary treatment for PMH.