Aneurysmal bone cyst inadvertently treated with chemotherapy-A series of three cases.

Aneurysmal bone cyst (ABC) is a benign locally aggressive tumor that occurs in childhood and early adulthood. Most relevant differential diagnoses are the telangiectatic osteosarcoma and the giant cell tumor. In the present case series chemotherapy following the EURAMOS or the Euro-Ewing 99 protocol was externally applied in three patients with the misdiagnosis of ABC as malignant bone tumor. In all three cases, a significant reduction of the volume of the ABC was achieved. This is the first report about the use of neoadjuvant chemotherapy in ABC. Chemotherapy reduces the size of an ABC and leads to progressive sclerosis.

Chondroblastoma: Is intralesional curettage with the use of adjuvants a sufficient way of therapy?

BACKGROUND: Chondroblastoma is a rare benign cartilaginous bone tumor that represents 1-2% of all primary bone tumors. It is characterized by aggressive growth, possible recurrence after surgical treatment and, in rare cases, metastasis. Surgical management is the primary treatment and includes intralesional curettage with or without adjuvants. Local recurrence rates vary between less than 10% up to more than 30%. METHODS: In this retrospective study between 2009 and 2020 we analysed 38 cases of chondroblastoma with a mean follow-up of 27.9 months who underwent a surgical treatment in our institution. Epidemiological data, radiographic and histological examinations, different surgical techniques, complications and local recurrence were evaluated to comment on the question if curettage with or without adjuvants is a sufficient way of therapy. RESULTS: The study includes 25 male (65.8%) and 13 female (34.2%) patients with a mean age of 17.2 (11-51) years. The most common location of manifestation was the proximal epiphyseal humerus (34.2%), followed by the proximal tibia (26.3%) and the distal femur (15.8%). Joint involvement occurred in 28 patients (73.7%). In all cases intralesional curettage was performed; in 25 cases (65.8%) the resulting cavity was filled with bone substitute, in 7.9% (3 cases) with bone cement and in 10.5% (4 cases) with autogenous bone graft. Adjuvant hydrogen peroxide was used in 64.9% of the cases. The overall recurrence rate was 39.5% (15 cases). The following subgroup analysis showed a recurrence rate of 100% (4/4 cases) after curettage and defect reconstruction with autogenous bone. In the case of intralesional curettage and filling of the cavity with bone substitute but without use of adjuvant the recurrence rate was 50% (4/8 cases). A low recurrence rate of 11.8% (2 cases) was observed in the case of intralesional curettage, using hydrogen peroxide as adjuvant (17 cases) and bone substitute for defect reconstruction. CONCLUSIONS: Chondroblastoma represents a rare pathology. Therapeutically an aggressive intralesional curettage with use of hydrogen peroxide as adjuvant and filling up the defect with bone substitute leads to low recurrence rates.

Right atrial cardiac myxoma and multiple pulmonary artery aneurysms: Is there a causal relationship?

Cardiac myxomas are rare occurrences in pediatric populations, as are pulmonary artery aneurysms. We report a 17-year-old adolescent with right atrial cardiac myxoma and concomitant multiple peripheral pulmonary artery aneurysms. Histological examination indicated infiltration of the pulmonary artery wall through the embolic cardiac myxoma cells, thereby weakening it. This report highlights the probable causal relationship between these two entities, proposes the possible pathomechanism and presents the diagnostic and therapeutic dilemmas in the management of this condition.