The expression of MDM2 in gastrointestinal stromal tumors: immunohistochemical analysis of 35 cases.

BACKGROUND: Gastrointestinal stromal tumors (GIST) are the most common primary mesenchymal tumors of the digestive system. The assessment of their biological behavior still remains a scientific challenge. To date, there are no well-established biological prognostic markers of GIST. Our aim is to study the expression of the MDM2 oncoprotein in GIST through an immunohistochemical analysis. METHODS: It was a retrospective study of 35 cases of GIST diagnosed from 2009 to 2012 in the department of pathology of Hassan II university hospital, Fès, Morocco. MDM2 immunohistochemical staining was performed on archival paraffin-embedded and formalin-fixed specimens (with a threshold of nuclear positivity > 10%). Analysis of correlations between MDM2 immunoexpression and clinicopathological features of GIST has been performed. RESULTS: The mean age was 55.23 years (range 25-84 years) with a male predominance (sex ratio = 1.5). The stomach was the main site of GIST, with 17 cases (48.57%) followed by the small bowel (9 cases, 25.71%). The spindle cell type GIST was the most frequent morphological variant (29 cases, 82.85%). Tumor necrosis was present in 8 cases (22.85%). Two patients (5.71%) had very low risk GIST, 5 (14.28%) had low risk GIST, 7 patients (20%) had intermediate risk tumors. The remaining 21 cases (60%) had high risk GIST. At the time of diagnosis, 9 patients (25.71%) had metastatic tumors. At immunohistochemical analysis, 40% of cases (14 patients) stained positive for MDM2. Of these MDMD2-positive tumors, 11/14 (78.57%) had high risk tumors and 8/14 cases (57.14%) presented with metastatic GIST. MDM2 positivity was significantly associated with the metastatic status (p = 0.001). CONCLUSION: The current study suggests that MDM2 immunohistochemical expression is a negative histoprognostic factor in GIST with a statistically significant correlation with metastasis.

Bone pathologic fracture revealing an unusual association: coexistence of Langerhans cell histiocytosis with Rosai-Dorfman disease.

BACKGROUND: The coexistence of Rosai-Dorfman disease (RDD) with Langerhans cell histiocytosis (LCH) is very rare, as to date only 17 cases have been reported in the english literature. The pathophysiology of this uncommon co-occurrence still remains enigmatic and a subject of various speculations. CASE PRESENTATION: We report a case of a 30-year-old female patient who presented with a pathologic fracture of the left proximal femur. Her medical history was unremarkable, there were no fever, skin lesions, lymphadenopathy or other organomegaly at physical examination. X-ray radiograph of the fractured femur showed an isolated and ill-defined osteolytic lesion. The histopathological analysis of biopsies from this lesion were consistent with a combined RDD-LCH of the bone. CONCLUSION: Combined RDD-LCH is a very rare phenomenon, whose pathophysiology still remains unclear and a subject of various speculations.

Prostate malignant tumor and benign prostatic hyperplasia microenvironments in black African men: Limited infiltration of CD8+ T lymphocytes, NK-cells, and high frequency of CD73+ stromal cells.

BACKGROUND: Anti-cancerous immunology has yet to be investigated in the African black population, despite being the dawn of precision medicine. AIM: Here we investigated the tumor microenvironment of prostate cancer and benign prostatic hyperplasia (BPH) in black Africans. METHODS: Through immunohistochemistry analysis of prostate cancer and BPH patients' biopsies, we investigated the expression and distribution of CD73, CCD8 T-lymphocytes, and natural killer cells. In addition, we looked at tumor-infiltrating features CD8 T-lymphocytes and natural killer cells. RESULTS: We show for the first time in black Africans a high expression of CD73 in epithelial-stromal cells and virtually no infiltration of CD8 T lymphocytes and natural killer cells in the tumoral area. In addition, CD73 was seven (7) times more likely to be expressed in prostate cancer stromal tissues than in benign prostatic hyperplasia tissues (odds ratio = 7.2; χ2 = 21; p < .0001). In addition, PSA concentration was significantly higher in prostate cancer patients than in BPH patients (p < .001). Also, the PSA-based ROC. analysis showed an area under the curve of 0.87 (p < .0001). CONCLUSION: CD73 expression is more likely expressed in prostate cancer stromal tissues than in benign prostatic hyperplasia tissues. The features of prostate cancer in Black Africans suggest CD73 expression as a possible target for immunotherapy in this population.

Isolated splenic lymphangioma presenting as a huge mass causing anemia and abdominal distension in an adult patient: a case report.

BACKGROUND: Lymphangiomas are uncommon benign lesions of lymphatic vessels very rarely affecting the spleen. Isolated involvement of the spleen in adult patients is rarely reported. CASE PRESENTATION: We report a case of a 40-year-old Arabic woman who presented with a 25-cm abdominal mass, fatigue, and anemia evolving for 6 months. Her physical examination revealed anemic syndrome and an enormous splenomegaly extending beyond the umbilical area. An abdominal computed tomographic scan showed a 25-cm splenic mass with multiple hypodense nodules without enhancement after contrast injection. A surgical total splenectomy was performed. Histopathological analysis led to the diagnosis of cystic splenic lymphangioma. The patient's postoperative course was uneventful, and she was discharged from the hospital. CONCLUSIONS: Isolated splenic lymphangioma in adult patients is very rare. The preoperative diagnosis is challenging because imaging techniques are not specific. Pathological analysis of the resected specimen is the only effective way to render the definitive diagnosis. Splenic lymphangiomas have a benign course after complete surgical resection.

Acute suppurative appendicitis associated with Enterobius vermicularis: an incidental finding or a causative agent? A case report.

BACKGROUND: Histological acute appendicitis patterns associated with Enterobius vermicularis is an extremely rare finding. The exact role of this parasite in acute appendicitis is controversial as usually resected specimens show no evidence of histological inflammation. CASE PRESENTATION: We present herein a case of a 21-year-old male Arabic patient who presented with clinical syndrome of acute appendicitis. Emergency appendectomy was performed and the histopathological examination of the resected specimen showed the presence of E. vermicularis as well as intense acute inflammatory patterns such as mucosal ulceration and suppurative necrosis. The post-operative course was uneventful and the patient was discharged with appropriate anti-helmintic drug prescription. CONCLUSION: Acute appendicitis due to E. vermicularis is a very rare occurrence. The histopathological analysis of resected specimens should pay special attention to search for this parasite for adequate post-operative treatment of patients.

Bilateral pheochromocytoma with ganglioneuroma component associated with multiple neuroendocrine neoplasia type 2A: a case report.

BACKGROUND: Composite pheochromocytoma/paragangliomas are very rare tumors composed of ordinary pheochromocytoma paragangliomas associated with neurogenic tumors. Several hereditary susceptibility disorders are known to be associated with pheochromocytoma/paragangliomas such as multiple endocrine neoplasia type 2 (2A or B). To the best of our knowledge, only four cases of composite pheochromocytoma/paragangliomas associated with multiple endocrine neoplasia type 2 have been reported. CASE PRESENTATION: A 40-year-old Arabic woman presented with headache, palpitations, paroxysmal hypertension, and weight loss, which she had had for the last 3 years. She had a familial history of diabetes and multiple endocrine neoplasia type 2. A radiological examination revealed thyroid lesions and bilateral adrenal medulla tumors. Our patient had undergone bilateral adrenalectomy, total thyroidectomy with cervical lymphadenectomy, and parathyroidectomy. A pathological examination confirmed the multiple endocrine neoplasia type 2A consisting of left medullary pheochromocytoma, right medullary composite pheochromocytoma-ganglioneuroma, medullary carcinoma of the thyroid with lymph node metastasis and parathyroid hyperplasia. A genetic analysis also revealed that our patient had a RET germline mutation. CONCLUSION: Composite pheochromocytoma/paraganglioma associated with multiple endocrine neoplasia type 2 is a very rare occurrence, as the current literature provides only a few cases. Further reported cases are needed in order to understand the behavior and the pathogenesis of this uncommon entity.

Unexpected pulmonary tumor: metastasis from a benign uterine leiomyoma in a post-menopausal woman: a case report.

BACKGROUND: The occurrence of lung metastasis from benign uterine leiomyomas is rarely reported especially in post menopausal women. The pathogenesis of these metastatic benign tumors still remains a subject of various speculations. CASE PRESENTATION: A 57-year-old woman presented with a chronic cough and dyspnea. She had undergone 8 years previously, hysterectomy for benign leiomyomas. A chest computed tomography scan showed a 4 cm solitary nodular parenchymal tumor that increased in size after 12 months. The histological analysis of the biopsy from this nodule showed a benign tumor with regular spindle cells disposed in intersected fascicles. At immunohistochemical analysis, the tumor cells were positive for smooth muscle markers and oestrogen-progesterone receptors with a low mitotic index assessed by Ki-67. These features were consistent with a benign metastasizing uterine leiomyoma. At the multidisciplinary meeting, prescription of an aromatase inhibitor has been decided for the patient. CONCLUSIONS: Benign metastasizing uterine leiomyomas of the lung are very rare tumors. Although extremely rare in post menopausal women, their diagnosis should be considered in symptomatic patients with a history of hysterectomy for leiomyomas.

Thymic large cell neuroendocrine carcinoma - a rare and aggressive tumor: a case report.

BACKGROUND: Neuroendocrine tumors are a large group of tumors with a wide spectrum of behavior, affecting mainly the digestive system and the lung. The thymus is very rarely affected. CASE PRESENTATION: A 28-year-old Arab woman presented with chronic chest pain and dyspnea. A computed tomography scan showed a huge anterior mediastinal mass invading neighboring structures. A mediastinotomy was performed with biopsies of the mass. Pathological findings were consistent with a thymic large cell neuroendocrine carcinoma. CONCLUSIONS: The occurrence of a large cell neuroendocrine carcinoma in the thymus, especially in young people, is extremely rare. In this current report, we discuss the clinicopathological issues of this rare tumor according to recent literature data.

An unusual site of metastasis: splenic metastastasis from a colon cancer.

Splenic metastasis from colorectal cancers is a very rare occurrence. Few cases have been reported in the literature. We report herein an additionnal case of metachronous splenic metastasis from adenocarcinoma of the sigmoid colon, 3 years after the diagnosis of the primary tumor. A 62-year old woman presented for regular follow-up after colectomy for sigmoid colon adenocarcinoma. A computed tomography-scan found two splenic metastatic nodules for which splenectomy had been performed. The histological analysis of the resected spleen showed a well-differentiated metastatic adenocarcinoma from colon. The patient recovered well after surgery, and 10 months after, she had no signs of the disease.