Intraosseousschwannoma: A Case Report and Review

Bony schwannoma is a rare benign tumour derived from Schwann cells of nerve fibres in the bone. It accounts for less than 1% of bony benign tumour, and prone to occur in the sacrum and mandible, occurrence in scapula is very rare. Here we report a 50-year-old woman with the chief complaint of pain in the left scapula. Imaging examination showed a giant, irregular, swelling lesion with distinct border involving the left scapula, extending into the left shoulder glenoid and pressing the surrounding soft tissues. Needle biopsy showed that the tumour was composed of spindle cells with S-100 protein positive, mimicking a benign neurogenic tumour. Then a complete excision was performed by removing the tumour and the surrounding tissues including partial left shoulder glenoid. Histologically, Antoni type A areas were the predominant microscopic pattern with occasional alternation by Antoni type B areas. Immunohistochemistry found that the neoplastic cells were scatteredly positive for S-100 protein. All these features suggest a diagnosis of an intraosseousschwannoma of the left scapula. Follow-up of the patient for ten months found no recurrence or sign of other tumours following complete tumour resection without any adjuvant therapy. In conclusion, this case of giant intraosseousschwannoma of the scapula is a rare benign bony tumour, and its diagnosis combined with clinical, imaging and pre-operative needle biopsy is important to guide further therapy, and avoid overtreatment.

Increased Eosinophilic Precursors in Megaloblastic Bone Marrow — An Interesting Observation

Megaloblastic maturation of erythroid precursors is seen in cases of vitamin B12 and folic acid deficiency and needs a thorough evaluation. In the present study we have evaluated 342 bone marrow aspiration smears by doing a thorough differential count and findings were recorded. In addition to giant metamyelocytes we have observed that eosinophilic precursors were significantly increased in 78% of the cases. Interestingly, none of them had eosinophilia in peripheral blood. Such finding was not reported in megaloblastic marrow till date to the best of our knowledge. All the patients had deficiency of cobalamine and folic acid either both or one of them with a characteristic megaloblastic maturation of the erythroid precursors. The reason for such finding can be hypothesized to be a result of various interleukins (IL-5, IL-3) and growth factors that play a major role in hemopoietic cell maturation. The awareness of this finding of eosinophilic precursors in increased percentages in a megalobalstic marrow is important because megaloblasts are also found in marrows with increased eosinophils like chronic eosinophilic leukemia and hypereosinophilic syndrome but they have peripheral eosinophilia in addition, which is absent in megaloblastic anemia.