Case 1
A 75-year-old man, without any significant medical history, presented to our hospital with persistent right shoulder pain in July 2023. On examination, he had severe shoulder pain with swelling and slight local heat and could not actively move his shoulder. MRI revealed a tumorous lesion in the right scapula, infiltrating the anterior and posterior aspects and the subacromial space (Fig. 1A and B). Positron emission tomography-computed tomography (PET-CT) showed a high maximum standardized uptake value (SUVmax) of 37.9 in the scapular lesion (Fig. 1C) and multiple pulmonary metastases. After being diagnosed with Ewing sarcoma, he received the VDC-IE chemotherapy (vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide). After three cycles, the multiple lung metastases nearly disappeared, prompting us to treat the scapular lesion with CIRT. The patient received three additional chemotherapy cycles followed by CIRT. After two more chemotherapy cycles, chemotherapy was halted due to prolonged pancytopenia and severe febrile neutropenia. At the end of treatment, PET-CT indicated a reduction in SUVmax to 3.59 in the local lesion and complete disappearance of pulmonary metastases. At two years post-treatment, there were no signs of local relapse or metastasis on MRI (Fig. 1D) and PET-CT, although scapular destruction persisted. He had a limited range of motion of the right shoulder (flexion, 40°; extension, 10°; abduction, 20°; external rotation, 0°; MSTS score, 70%).
Case 2
A 40-year-old man presented to our hospital with a tumor on his left scapula, with shoulder pain, and swelling 3 months prior to his first visit in August 2023. The patient was diagnosed with Hodgkin's lymphoma at 25 years of age and treated with chemotherapy that included doxorubicin. Shoulder motion was not restricted, except for a slight disturbance of internal rotation. MRI and PET-CT revealed a tumor extending to both the ventral and dorsal aspects of the left scapula (Fig. 2A and B). The patient was diagnosed with Hodgkin lymphoma at 25 years of age, which was treated with chemotherapy that included doxorubicin. To prevent doxorubicin-associated cardiotoxicity, we replaced it with actinomycin-D in the VDC-IE regimen. Two years after treatment, PET-CT and MRI (Fig. 2C) revealed no metastasis or local recurrence. The active range of motion of the shoulder was as follows: forward flexion, 90°; extension, 30°; abduction, 60°; external rotation, 10°; internal rotation, S1; and MSTS score, 87%.
Case 3
An otherwise healthy 32-year-old woman was referred to our hospital with a suspected malignant tumor of the right scapula. She noticed a prominence around the shoulder 4 months before visiting us and consulted several clinics; however, the cause of the symptoms was not revealed. On the first visit to our hospital in April 2023, she presented with pain in motion and swelling, with slight redness around the shoulder. MRI revealed a tumor with unclear borders and surrounding inflammation on the scapula, eroding the dorsal cortex (Fig. 3A). PET-CT showed a high SUVmax in the dorsal scapular lesion (Fig. 3B) and multiple pulmonary metastases. After four cycles of VDC-IE, PET-CT revealed a reduced accumulation in her multiple lung metastases. Based on the PET-CT results indicating that the metastases were manageable, we chose to treat the scapular lesion with CIRT. CIRT was administered, followed by two additional cycles of VDC/IE. After the 12th of 17 scheduled cycles of chemotherapy (10 months later from the initiation of VDC-IE regimen), the recovery from myelosuppression was significantly prolonged, and follow-up CT revealed that the pulmonary metastases had grown. The chemotherapy regimen was modified to irinotecan (CPT-11) and temozolomide (TMZ) due to these issues. After the fourth cycle of CPT-11/TMZ, she developed fever, severe pain from the axilla to the back, and an exacerbation of dermatitis. Based on the clinical findings, radiation recall dermatitis was therefore suspected. One month of steroid and narcotic medications alleviated her symptoms. Due to the addition of prednisolone to prevent radiation recall, the patient underwent a total of 20 cycles of CPT-11/TMZ, which kept the growth of the patient's lung metastases gradual, even now, three years after starting treatment. Two years after the initiation of treatment, the patient's active range of motion in the right shoulder was as follows: forward flexion, 150°; extension, 30°; abduction, 150°; external rotation, 65°; internal rotation, S1; and MSTS score, 87% (Fig. 3C).
The biopsy specimens from the three cases were fixed in 10% neutral buffered formalin at room temperature for 24 h, dehydrated in a graded ethanol series, cleared in xylene and embedded in paraffin. For histological evaluation, 4-µm sections were deparaffinized, rehydrated and stained with Tissue-Tek® Gill's Hematoxylin (cat. no. 8648; Sakura Finetek) and Tissue-Tek® Eosin (cat. no. 9134-4P; Sakura Finetek) at room temperature using a Tissue-Tek Prisma® Plus Automated Slide Stainer (Sakura Finetek) according to the manufacturer's protocol.
For immunohistochemical analysis, 3-µm sections were processed using the BOND Polymer Refine Detection system (Leica Biosystems), including the secondary antibody, following the manufacturer's instructions. Briefly, the sections were incubated for 15 min at room temperature with the following ready-to-use antibodies: Mouse monoclonal antibodies against CD99 (clone 12E7; cat. no. IR057; Dako; Agilent Technologies, Inc.), CD3 (clone LN10; cat. no. PA0553; Leica Biosystems), CD20 (clone L26; cat. no. PA0200; Leica Biosystems), CD56 (clone CD564; cat. no. PA0191; Leica Biosystems), CD138 (clone B-A38; code no. 413881; Histofine), chromogranin A (CGA; clone 5H7; cat. no. PA0515; Leica Biosystems), and synaptophysin (clone 27G12; cat. no. PA0299; Leica Biosystems); and a rabbit monoclonal antibody against cyclin D1 (clone EP12; cat. no. PA0046; Leica Biosystems). The sections were then incubated with the pre-diluted secondary antibody for 10 min and counterstained with hematoxylin for 5 min at room temperature. Staining was visualized using a light microscope (Imager A2; Carl Zeiss AG).
Histologically, the specimens showed a proliferation of small round cells with scant cytoplasm, which were positive for Periodic acid-Schiff staining and CD99, but negative for epithelial markers. Fig. 3 shows representative specimens of Case 3. Small round cells that overlapped and had hyperchromatic nuclei diffusely proliferated with a palisading pattern around the vasculature and rosette-like formation (Fig. 4A). The immunohistochemistry results were as follows: CD20(−), CD3(−), CD138(−),CD56(−), CGA(−), synaptophysin(−), CD99(+) (Fig. 4B), Cyclin D1(+) (Fig. 4C), and AT1(−). In addition, negative results for WT-1 and calretinin suggested that the tumor was unlikely to be a CIC-rearrangement tumor. Based on the pathological, radiological, and physical findings, the patient was diagnosed with Ewing sarcoma.
Only case 3 was analyzed with the GenMine TOP Cancer Genome Profiling System, which detected the EWSR1-FLI1 fusion. The National Health Insurance system in Japan covers limited molecular biological analyses, including fluorescence in situ hybridization. To undergo insurance-covered cancer gene panel testing, patients with solid tumors must meet specific criteria, such as having no available standard treatment or having completed (or are expected to complete) standard treatment. Cases 1 and 2 were not analyzed for fusion genes because they achieved a complete disease-free status with chemotherapy and CIRT.