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.

[Metastatic bladder metachrone to a kaposi sarcoma cancer at a therapeutic impasse: about a case]. / Impasse thérapeutique pour une tumeur de la vessie métastatique métachrone à un sarcome de kaposi: à propos d'un cas rare.

Chemotherapy is the treatment of choice for a metastatic urothelial bladder cancer. We here report a rare case of metastatic bladder cancer associated with Kaposi sarcoma posing a serious risk of aggravation of the new neoplasia. It was necessary to entrust the patient to his family.

Penile metastasis from rectal adenocarcinoma: a case report.

BACKGROUND: Despite its rich vasculature, the penis is rarely involved by metastasis. Since the first description of penile metastasis in 1870, fewer than 500 cases have been reported in the literature. The pelvic organs are the main source of primary tumors that metastasize to the penis. CASE PRESENTATION: We report a case of a 46-year-old Arabic man who presented with erectile dysfunction and painful induration of the penile root. Eight months ago, he had undergone abdomino-perineal resection for rectal adenocarcinoma after neo-adjuvant chemotherapy. The histological evaluation of the resected specimen disclosed a ypT3N0 tumor with a poor therapeutic response (around 5%). An adjuvant chemotherapy by XELOX (oxaliplatin plus capecitabine) regimen has been prescribed for the patient. The magnetic resonance imaging (MRI) showed tumoral infiltration of penile structures and a biopsy of the corpora cavernosa was performed. The histological examination disclosed a penile metastasis from the patient's previous rectal adenocarcinoma. The patient is still alive and continues his adjuvant therapy. CONCLUSION: Penile secondary tumors are very rare and usually occur in patients with advanced tumor stages. A diagnosis of penile metastasis should be considered in patients with a history of malignancies who present with genitourinary symptoms. These patients have a dismal prognosis as they often die in the year after the diagnosis.

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.