MPLW515L mutation in acute megakaryoblastic leukaemia.

The thrombopoietin receptor gene (MPL) is expressed in megakaryocytes and exhibits the gain of function point mutation W515K/L in approximately 5% of patients with primary myelofibrosis/idiopathic myelofibrosis (PMF) representing one subtype of the chronic myeloproliferative disorders (myeloproliferative neoplasm). A series of primary and secondary acute myeloid leukaemias (AML) with megakaryoblastic phenotype and myelofibrosis unrelated to PMF (n=12) was analysed for the MPL(W515K/L) mutation by pyrosequencing. In three cases (25%), MPL(W515L) was found and in two of these a combination with trisomy 21 or the Philadelphia chromosome occurred. None of the secondary AML cases evolving from pre-existing PMF showed MPL(W515K/L) (n=4). We conclude that MPL(W515L) occurs in a considerable proportion of acute megakaryoblastic leukaemias with myelofibrosis unrelated to PMF.

[Metastatic placental site trophoblastic tumor. Diagnosis after pneumothorax]. / Metastasierter "Placental-site-Trophoblasttumor". Diagnose anlässlich eines Spontanpneumothorax.

Placental site trophoblastic tumor (PSTT) is a rare, mostly benign tumor, which in 10-15% of cases shows a malignant behavior. The case of a 35 year old woman with pulmonary metastasis of a PSTT is reported. This finding was incidental in an atypical lung-resection due to pneumothorax. The literature on this rare tumor entity is reviewed especially in terms of differential diagnosis, biological behavior and association with a pneumothorax.

[Incidental chorangiocarcinoma. Case report, immunohistochemistry and theories of possible histogenesis]. / Inzidentelles Chorangiokarzinom. Fallbericht, Immunhistochemie und Theorien zur möglichen Histogenese.

We describe the third case world-wide of a chorangiocarcinoma, a tumour with an abnormal trophoblast proliferation in combination with a hypervascular chorangiosis of the villous stroma. The lesion was an incidential finding by a healthy 31-year-old woman, gravida 1, para 1 when the pregnancy was terminated at 34 weeks gestation because of fetal distress and intrauterine growth restriction. Hormonal levels were within the normal range. Mother and infant had an uneventful postpartum course. Immunohistochemical studies of the abnormal trophoblasts demonstrated strong immunoreactivity for HCG and in 80% for Ki 67. The semiquantitative expression of angiogenic growth factors (VEGF, bFGF, Ang-1 und Ang-2, PDGF) in the tumour trophoblasts was similar to that seen in the normal villi. The pathogenesis of this tumour with a villous vascular response is curious and unclear. Possibilities include the occurrence of a variant of a chorion carcinoma, the occurrence of a new tumour entity or of two separate lesions, a chorangioma and incidential chorion carcinoma, present together as a "collision" tumour. Another possibility is a composition tumour or a reactive lesion of trophoblasts and the villous vascular tree.

[Leiomyosarcoma of the spermatic cord. A case report with review of the literature]. / Leiomyosarkom des Samenstrangs. Ein Fallbericht mit Literaturübersicht.

The case of a 68-year-old man with leiomyosarcoma of the spermatic cord is reported. Radical orchiectomy with high ligature of the cord was performed. Pathological examination including immunohistochemistry demonstrated a leiomyosarcoma which seemed to arise from a spermatic cord vessel.

[Ectopic meningioma of the tonsil]. / Ektopes Meningeom in der Tonsille.

To our knowledge this is the first reported case of a primary extracranial meningioma located in the palatine tonsil. Immunohistochemical investigation of the tumour showed coexpression of vimentin and neuron-specific enolase (NSE). No staining was found with antibodies against cytokeratins KL1, 13/10, 8 and 18, epithelial membrane antigen EMA and melanoma protein (HMB-45). It seems justifiable to classify this tumour as an atypical meningioma because of the local increased mitotic activity.

[Morphology and prognosis of follicular thyroid cancer--a clinico-pathologic and DNA cytometric study of 95 tumors]. / Morphologie und Prognose des folliculären Schilddrüsencarcinoms--Eine klinisch-pathologische und DNS-cytometrische Untersuchung an 95 Tumoren.

A retrospective study of 95 follicular thyroid carcinomas was conducted to evaluate the prognostic value of different morphological and clinical features. The biological behaviour of these tumours was primarily influenced by presence or absence of a capsule type of confinement: the frequency of lethal outcome among widely invasive carcinomas was six times higher than among encapsulated neoplasms. Furthermore, dismal prognosis could be demonstrated for tumours occurring in older patients (with a sharp break in the prognosis at the age of 52 years) and for those lesions which displayed oxyphilic metaplasia. The same effect was shown for presence of lymph node metastasis, tumour invasion of the cervical soft tissue and, for the case of encapsulated carcinomas, distant haematogenous spread. Conversely, the degree of differentiation and the patients' sex proved to have no significant influence on prognosis. In 22 carcinomas, cytophotometric and flow-cytometric determinations of DNA values were performed. These procedures revealed to have only limited diagnostic value, since for the majority of the tumours, benignancy or malignancy could not be judged from the DNA histograms. However, DNA measurements proved to contribute valuable information for the prognosis in individual cases of widely invasive follicular carcinomas. The discussion focuses on the diagnostic, therapeutic and prognostic relevance of these findings and on their impact on subclassification of follicular thyroid carcinomas.