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Purpose. Microsatellite instability (MSI) caused by mismatch repair protein (MMRP) deficiency is detected in 15% of sporadic colorectal cancers (CRCs). Our aim is to investigate the frequency of MMRP deficiency in young CRC patients, using immunohistochemical analysis. Methods. This study targeted cases of CRC at King Hussein Cancer Center from 2004 until 2012 in patients 45 years of age or younger at the time of diagnosis. Clinicopathological data was obtained from 155 patients’ records. Immunohistochemistry for MLH1, MSH2, PMS2, and MSH6 proteins was performed on paraffin-embedded tissue containing carcinoma. Results. The median age of patient at diagnosis was 38 years. A total of 29 (19%) cases showed deficient MMRP(dMMRP)expression. Loss of expression of PMS2 was seen in 17 cases, 12 cases of which showed loss of MLH1 expression. Loss of expression of MSH6 was seen in 10 cases, 9 of which showed loss of MSH2 expression. One case (3.4%) showed loss of all four MMR proteins, and another case (3.4%) showed loss of PMS2/MLH1 and MSH6. There was a significant association between abnormal MMR protein expression and tumor location proximal to splenic flexure (p value 0.000), pathologic features suggestive of microsatellite instability (p value 0.000), P53 negativity (p value 0.000), and stage (p value 0.02). Patients with dMMRP CRC appeared to have a significantly better overall survival compared to patients with proficient MMRP(pMMRP)(p value 0.02). Loss of MSH2/MSH6 was significantly associated with positive family history of cancer (p value = 0.020). Conclusions. The prevalence of dMMRP tumors in this age group appears to be similar to international literature. dMMRP tumors tends to be associated with earlier stages and better outcomes compared to pMMRP cases. dMMRP can serve as a biomarker for better prognosis. These results are of value in directing the clinical management of young patients with CRC.

Objective: Langerhans cell histiocytosis (LCH) is an uncommon entity of unknown etiology. It contains a wide range of clinical presentations. The discovery of oncogenic BRAF V600E mutation in LCH has provided additional evidence that LCH is a neoplasm. Papillary thyroid carcinoma is the most common cancer of the thyroid characterized by a high incidence of BRAF V600E mutations. LCH with concomitant PTC is rare, with few cases reported in the literature. Cases summary: We identified two cases of LCH with concomitant papillary thyroid carcinoma in adult patients. The first was a 49-year-old female with a thyroid nodule diagnosed with papillary thyroid carcinoma. Later, the patient had a left neck mass; Ultrasound-guided lymph node FNA was diagnosed with Langerhans histiocytosis. Subsequently, a chest CT scan revealed signs of Langerhans cell histiocytosis in the lung. The second case refers to a 69-year-old male who presented with a left thyroid nodule diagnosed on FNA cytology as papillary thyroid carcinoma. The patient was found to have multiple bone lytic lesions. Biopsies revealed Langerhans cell histiocytosis. Later, the patient experienced LCH involvement of the bone marrow with associated secondary myelofibrosis. Conclusions: LCH is rare in adults; the association with papillary thyroid carcinoma is reported and should be considered in the presence of Langerhans cell groups along with PTC, whether in the thyroid gland or cervical lymph nodes. Once LCH has been diagnosed, pulmonary involvement should also be investigated. This will direct treatment plans for patients with pulmonary or systemic disease involvement.

Introduction and Importance: Adult Pilocytic Astrocytomas (APA) are infrequent low grade tumors. While supratentorial APA is considered rare, insular APA is extremely rare. Case presentation We present a case of pure insular APA along with surgical outcomes. Tractography and functional MRI were obtained pre-operatively. The patient underwent neuro-navigation guided microsurgical resection with sub-cortical white matter mapping, utilizing Intra-operative MRI guidance. The Sylvain fissure was opened to secure the M3 branches, and near total resection was achieved. Clinical discussion APA in the insula is a very rare presentation and is considered challenging. Its proximity to the middle cerebral and lenticulostriate arteries, motor areas, and language areas makes accessing and resecting the tumor challenging. A multidisciplinary approach by an experienced team is needed to plan the management of young adult patients and reach the best outcomes. Conclusion Implementing microsurgical techniques, modern imaging modalities and intraoperative mapping helps to achieve maximal safe resection without risking functions.