Synchronous Schwannoma and Gastrointestinal Stromal Tumor in Small Intestine – A Rare Case

Introduction/Objective Small bowel Schwannoma is a benign neoplasm of nerve sheath cells. The Gastrointestinal stromal tumor (GIST) constitutes only about 1-2% of small bowel spindle cell tumors. The simultaneous presence of two tumors in the small bowel is extremely uncommon. Methods/Case Report We report a case of small bowel GIST co-existing with Schwannoma. A 64-year-old female with a known history of Neurofibromatosis was admitted for excision of a small bowel tumor. MRI of the abdomen revealed two enhancing lesions in the left upper quadrant adjacent to the small bowel. Differential considerations included GIST versus Neurofibroma. Left hemicolectomy with small bowel resection was performed. The proximal small bowel revealed GIST, spindle cell type, low risk (3.5 cm), low grade (<5 mitoses/ 5mm2). Tumor cells were diffusely reactive to CD34, CD117, and DOG1 immunostains and were nonreactive to S100 and SOX10 immunostains confirming the diagnosis of GIST. Another segment of the small bowel revealed a 1.5 cm well-circumscribed, predominantly spindle cell tumor with abundant myxoid stroma and prominent cyst formation. Tumor cells were diffusely reactive to S100 and SOX10 immunostains but nonreactive to CD34, CD117, and DOG1, favoring a diagnosis of Schwannoma. Gastrointestinal Schwannomas may be associated with Neurofibromatosis in some cases. GIST, a KIT- or PGDFRA-signaling driven mesenchymal tumor has also rarely been reported to be associated with Neurofibromatosis type 1. However, synchronous small bowel Schwannoma and GIST represent a rare co-existence of two different histopathologic subtypes of spindle cell tumors. Results (if a Case Study enter NA) NA Conclusion In summary, we present the rare co-existence of two different spindle cell lesions in Neurofibromatosis patient.

Malignant spindle cell tumors of the posterior fossa in children: case series and review of management

OBJECTIVE The WHO Classification of Tumours of the Central Nervous System (2016) classifies nonmeningothelial malignant spindle cell tumors involving the extraaxial tissues of the posterior fossa as melanocytic tumors and malignant mesenchymal tumors (sarcomas). The objective of this study was to conduct a review of the literature pertaining to the management strategies of posterior fossa malignant spindle cell tumors in the pediatric population. METHODS The authors performed an institutional search of their pathology database for patients younger than 18 years of age who presented with posterior fossa malignant spindle cell tumors. A literature review was also performed using the PubMed database, with “posterior fossa” or “spindle cell tumors” or “Ewing sarcoma” or “high-grade” or “spindle cell sarcoma” or “leptomeningeal melanocytoma” as keywords. The database search was restricted to pediatric patients (age ≤ 18 years). Parameters reported from the literature review included patient age, tumor location, presenting symptoms, treatment modalities (resection, chemotherapy, and/or radiotherapy), leptomeningeal spread at or after the time of treatment, and follow-up length and resulting outcome. RESULTS The authors report 3 rare cases of posterior fossa malignant spindle cell tumors, including Ewing sarcoma in a 13-year-old male; high-grade spindle cell sarcoma, not otherwise specified in a 10-year-old male; and primary leptomeningeal melanocytoma in a 16-year-old female. All 3 patients underwent resection and radiotherapy and either chemotherapy or targeted immunotherapy. At the last follow-up, all patients were alive with either resolution or stable disease. CONCLUSIONS A review of these 3 cases and the existing literature support managing patients with intracranial malignant spindle cell tumors with multimodal therapy that can include a combination of resection, radiotherapy, and chemotherapy or immunotherapy to prolong progression-free and overall survival.

Nasal spindle cell tumor with rhabdomyoblastic features: A rare and diagnostically difficult case

Nasal spindle cell rhabdomyosarcoma is very rare. The tumor is sometimes confused with other spindle cell tumors. We herein report a case of nasal spindle cell tumor in a 62-year-old woman. The patient first presented herself to a medical doctor’s office after an episode of left epistaxis. An intranasal tumor was found and resected. The tumor was composed of spindle cells, and she was diagnosed with desmoid-type fibromatosis. Five years after the initial episode, an intranasal tumor was found again. The tumor showed a fascicular growth pattern with high cellularity and was predominantly composed of spindle cells. Scattered eosinophilic rhabdomyoblasts were also observed. She was diagnosed with spindle cell rhabdomyosarcoma. This is a unique case report not only because nasal spindle cell rhabdomyosarcoma is very rare but also because the tumor was initially diagnosed as desmoid-type fibromatosis. It is important to consider spindle cell rhabdomyosarcoma as a differential diagnosis of nasal spindle cell tumors.