A. Georgii

The differentiation of atypical adenomas and encapsulated follicular carcinomas in the thyroid gland

From 1968 to 1977 a total of 1,394 follicular neoplasms were seen in surgical material containing 4,612 thyroid glands. 1,159 tumors were obviously benign adenomas. All remaining follicular tumors with equivocal histological appearances were extensively re-examined, together with all apparently invasive follicular carcinomas. Thereby, 125 atypical adenomas, 55 encapsulated and 55 widely invasive follicular carcinomas were diagnosed. In 102 tumors a definite diagnosis was reached after excision and histological examination of ten tissue blocks from preserved wet material. In each case the number of blood vessel invasions and penetrations of tumor capsule was recorded. Among these tumors, 17/36 (47%) encapsulated carcinomas proved to be only slightly invasive. All their tissue blocks were cut into sequential sections and in 6/17 cases additional vascular invasions found. It was shown by this study that the proof of vascular invasion is more often successful than the proof of capsular penetration and therefore a better indication of malignancy in encapsulated follicular tumors. Examination of 10 tissue blocks represents the minimum effort to estimate the invasive capability of a follicular tumor, whereas sequential sections through less than 10 blocks are of little help in most cases. A follow-up study of all patients included here seems to justify the distinction we have made between atypical adenomas and encapsulated follicular carcinomas. In den Jahren 1968–1977 wurden insgesamt 1394 follikuläre Tumoren der Schilddrüse in einem Operationsgut von 4612 Strumen diagnostiziert. 1159 follikuläre Tumoren waren zweifelsfrei als Adenome einzuordnen. Alle übrigen follikulären Tumoren mit zunächst unklarer Dignität aber auch solche mit eindeutig invasivem Wachstum wurden histologisch eingehend nachuntersucht. Daraus resultierten 125 atypische Adenome, 55 weitgehend abgekapselte follikuläre Carcinome und 55 ausgedehnt invasive Carcinome. Bei 102 Tumoren stützte sich die endgültige Diagnose auf die histologische Nachuntersuchung von 10 Gewebsentnahmen aus dem kapselnahen Bereich. Dabei wurde die Zahl der Tumoreinbrüche in prae- oder postcapilläre Blutgefäße und die Zahl der kompletten Kapseldurchbrüche registriert. Bei 17/36 (47%) abgekapselten Carcinomen waren jeweils nur ein oder zwei Gefäßeinbrüche festzustellen. In diesen Fällen wurden die vorhandenen 10 Gewebsblöcke pro Tumor in 20 weiteren Schnittstufen aufgearbeitet und bei 6/17 zusätzliche Gefäßeinbrüche gefunden. Die quantitative Auswertung hat ergeben, daß der Nachweis von Gefäßeinbrüchen häufiger gelingt als der von Kapseldurchbrüchen und damit ein besserer Hinweis für die Malignität eines abgekapselten follikulären Tumors ist. Allerdings ist die Untersuchung von 10 Entnahmestellen das Minimum für eine zuverlässige Diagnose und mit Sicherheit nicht durch Schnittstufen mit weniger Gewebsblöcken zu erreichen. Der bisherige postoperative Verlauf aller in dieser Studie erfaßten Patienten rechtfertigt die nach den angegebenen Kriterien vorgenommene Unterscheidung zwischen atypischen Adenomen und abgekapselten follikulären Carcinomen.

Myelofibrosis in primary myelodysplastic syndromes: a retrospective study of 352 patients.

Abstract:  In a retrospective study of 352 patients with primary myelodysplastic syndromes, 61 (17.3%) revealed myelofibrosis in bone marrow biopsies. The fibrosis was observed to occur mostly focally (41/61 cases), and collagen deposits were found very rarely (4/61). The histopathology of bone marrow biopsies revealed hyperplasia and disturbed differentiation in megakaryopoiesis; the frequency and grade of dysplasia in megakaryopoiesis increased with advancing myelofibrosis. Reticulin fibrosis occurred in all subtypes of MDS; however, there was a higher incidence in chronic myelo‐monocytic leukaemia (CMMoL). The frequency of cytogenetic aberrations was significantly higher in the MDS cases with myelofibrosis, compared to the cases without fibrosis. Clinical data showed significantly lower values of haemoglobin and lower platelet counts in MDS with myelofibrosis. Life expectancy was reduced to 9.6 months, compared with 17.4 months in MDS without fibrosis. In refractory anaemia, the survival times were 10.0 months in MDS with myelofibrosis, compared to 28.9 months in MDS without myelofibrosis. 36.6% of the patients with MDS and myelofibrosis developed a transformation into ANLL during the course of the disease. Myelofibrosis therefore seems to herald a poor prognosis.

Effects of antigen retrieval by microwave heating in formalin-fixed tissue sections on a broad panel of antibodies

Formaldehyde fixation of biopsy specimens for routine purposes has often been held responsible for the poor reproducibility of immunohistochemical studies. Recently, antigen retrieval (AGR) using microwave irradiation was described as a potential tool to enhance immunostaining. A comparison of conventional staining and staining after microwave heating was performed for 52 markers, using tissues fixed in formaldehyde for 24 h, 1 to 6 weeks and 3 years respectively, as well as consultant case material. After adequate duration of fixation (24 h), only a few markers (17%) showed better results after AGR, but this percentage was increased to 50% when tissues were fixed for longer periods. Maximal enhancement was obtained in the group of consultant cases (58% of tested markers demonstrated better staining results), in which the period of fixation and tissue processing was unknown. To achieve reliable enhancement with AGR, continuous heating (100° C) should not be shorter than 20 min. In conclusion, AGR may become the most important tool to simplify and equalize immunohistochemical techniques, if critically evaluated.

Hypoplastic myelodysplastic syndrome: incidence, morphology, cytogenetics, and prognosis

SummaryThe present study, based upon the retrospective evaluation of 352 patients with primary myelodysplastic syndrome (pMDS), revealed hypoplastic MDS in 42 patients (11.9%). Median age is similar in hypo- and normo-/hypercellular MDS (72.6 versus 70.7 versus 72.4 years). Hypoplastic MDS occurred significantly more often in women compared with normo- and hypercellular MDS. Sequential biopsies were performed in 14 patients, showing a persistence of hypoplasia over a period of up to 43 months. The proportion of patients showing mesenchymal reaction, especially an increase of mast cells, was significantly higher in hypoplastic MDS, whereas dysplastic features of hematopoiesis occurred less frequently and were of lower grade in comparison to normo-/hyperplastic MDS. Among the subgroup with hypoplastic bone marrow, the classification according to FAB criteria revealed 28 patients with RA (66.7%), three with RARS (7.1%), and eight with RAEB (19.0%), as well as one patient each with RAEB-T and CMMol (2.4% each), and one case which had to be reckoned among the category of unclassifiable MDS (2.4%). Median survival was 21.8 months for hypoplastic MDS, 26.9 months for normoplastic MDS, and 14.2 months for hyperplastic MDS. During follow-up, 14 patients (33%) with hypoplastic MDS developed acute nonlymphatic leukemia. Although not a constant finding, karyotype abnormalities involving particularly chromosome 7 seem to be associated with hypoplastic MDS. The results confirm the existence of a hypoplastic variant of MDS which seems to more frequently affect female patients, and which requires bone marrow biopsy for its accurate diagnosis.

Chronic megakaryocytic granulocytic myelosis — CMGM

In 1,083 core biopsies of the bone marrow with myeloproliferative diseases 454 cases or 42% were found to have neoplastic megakaryopoiesis. Neoplasia of megakaryocytes was assumed from the conspicuous cytological atypicality revealed by light microscopy, extending and confirming earlier ultrastructural findings. Histopathology of the bone marrow in these patients was described as chronic megakaryocytic-granulocytic myelosis — CMGM — since neutrophilic granulopoiesis is also apparently neoplastic and both cell lineages showed a complete differentiation to mature forms. CMGM should be separated from the chronic granulocytic leukemia — CGL — which consists of only a single line proliferation. The incidence of CGL in our total of 1,083 patients was 25%. Both entities are included in chronic myeloid leukemia — CML — because of the demonstration of the Philadelphia chromosome in the hematopoietic cells of these two groups of patients. Primary or idiopathic thrombocythemia has to be differentiated from CMGM since there is no evidence for malignancy of the granulocytic series.

Histologic findings in bone marrow biopsies of patients with thrombocythemic cell counts

SummaryHistologic diagnoses from bone marrow biopsies were analyzed in a total of 1165 patients presenting with thrombocythemic platelet counts at initial examination. Two cut-off points suggested by the Polycythemia Vera Study Group to define thrombocythemia by platelet counts were compared: the former limiting value of 1000×109/l platelets versus the recently proposed value of 600×109/l. The percentage of all nonproliferative disorders was 41% under the lower, dropping to 11% under the high cut-off point. The respective figures for myeloproliferative disorders increased from 49% under the lower to 74% under the high limiting value. Primary thrombocythemia was included in 72% by the lower, and in only 40% by the high limiting value when classified by its histologic pattern in bone marrow biopsy. A striking decrease of platelet counts occurs, related to fiber increase, among each of three main groups of myeloproliferative disorders: in CML with megakaryocytic predominance from 40% down to 25%, in megakaryocytic-granulocytic myelosis (primary, i.e., agnogenic myelofibrosis) from 36.6% to 10%, and in primary thrombocythemia from 72.6% to 28.6% in cases with reticulin sclerosis.

Life expectancy in primary myelodysplastic syndromes: a prognostic score based upon histopathology from bone marrow biopsies of 569 patients.

Abstract:  The retrospective evaluation of bone marrow biopsies of 569 patients with primary myelodysplastic syndrome ‐ pMDS ‐ revealed 256 refractory anemias ‐ RA ‐, 52 refractory anemias with ringed sideroblasts ‐RARS ‐, 133 refractory anemias with excess of blasts ‐ RAEB ‐, 52 refractory anemias with excess of blasts in transformation ‐ RAEB‐t ‐, and 53 chronic myelo‐monocytic leukemias ‐ CMMOL ‐ according to FAB‐criteria, 23 patients were not otherwise specified (myelodysplastic syndrome: not otherwise specified ‐ MDS.NOS ‐). RARS‐patients had the best prognosis (median survival 41.9 months, incidence of leukemia 3.8%), followed by RA‐patients (26.5 months, 16.4%), MDS.NOS‐patients (22.4 months, 21.7%), CMMOL‐patients (12.5 months, 49.1%). RAEB‐and RAEB‐t‐patients had the worst prognosis (median survival time 8.5 and 4.6 months, incidence of leukemia 42.1% and 57.7%, respectively). But the survival times showed a considerable range in each FAB‐subgroup with 0–154 months in RA or 0–52 months in CMMOL. To forecast life expectancy more precisely, a scoring system was developed using nine histopathological parameters, among which the three most important ones were determined: quantity of myeloblasts, myelofibrosis and ALIPs. The scoring system allows a determination of three risk groups with significantly different survival times. It is valid also for patients without increase of myeloblasts (<5% myeloblasts in the bone marrow) and identifies high‐risk MDS patients in this group. By this proposed scoring system, a prognostic approval in primary MDS can be achieved applying histopathology without regarding further methods herewith presenting a system which could be considered independently from hematologic, cytological or laboratory data.

The impact of megakaryocyte proliferation for the evolution of myelofibrosis Histological follow-up study in 186 patients with chronic myeloid leukaemia

A histological study on sequential bone marrow biopsies in patients with chronic myeloid leukaemia (CML) was performed. We wished to answer the question as to whether a different content of megakaryopoiesis in the bone marrow of CML patients has a prognostic significance for the development of myelofibrosis during the course of disease. In addition, the significance of possible changes in the quantity of megakaryopoiesis in this process was assessed. In 186 patients who had no fibre increase at first diagnosis, the rate of subsequent myelofibrosis varied from 19% for the common or granulocytic subtype (CML.CT) to 40% for patients with features of megakaryocytic increase (CML.MI). No significant differences were found either in the rapidity of progression to fibrosis or in the final rate of osteomyelosclerosis. Whereas in CML.MI most patients (75%) showed an increase of fibres only, this was accompanied by an additional increase of megakaryocytes in CML.CT, changing the histological pattern from CML.CT to MI or MP, respectively. The data therefore revealed a correlation between fibre increase and subtyping of CML as suggested by the Hannover classification of chronic myeloproliferative diseases. Subtypes of CML with megakaryocytic increase could be shown to present a “pre-myelofibrotic” stage of disease and may therefore be conceived as a particular pathway of acceleration.

A new histological embedding method by low-temperature polymerisation of methyl methacrylate allowing immuno- and enzyme histochemical studies on semi-thin sections of undecalcified bone marrow biopsies

SummaryA new procedure of embedding in methyl methacrylate (MMA) is introduced, which enables immunostaining by preservation of cellular epitopes. This could be achieved by reduction of polymerisation temperature from ca. 60° C to 22° C within the core of tissue blocks. Reduction of the polymerisation temperature is due to destabilisation of acrylate monomer, reduction of catalyst, exclusion of molecular oxygen, chemical initiation and reduction of environmental temperature. This results in good preservation of antigens and enzymes in the haematopoietic and lymphatic tissue of bone marrow as well as lymphoid, epithelial and mesenchymal markers in other tissues, comparable to paraffin embedding. Results are demonstrated by application of monoclonal and polyclonal antibodies and by demonstration of enzyme activity conventionally used in haematology.

Expression of proliferation associated antigens and detection of numerical chromosome aberrations in primary human liver tumours : relevance to tumour characteristics and prognosis

AIMS: To assess cell proliferation and the presence of numerical chromosome aberrations involving chromosomes 1 and 8 in benign and malignant liver tumours. METHODS: Cell proliferation was studied immunohistochemically in paraffin wax embedded material from 62 primary liver tumours (20 hepatocellular carcinomas, 16 cholangiocellular carcinomas, 15 liver cell adenomas, 11 focal nodular hyperplasias), and the results were compared with histological characteristics and clinical data. Copy numbers of chromosomes 1 and 8 were assessed by interphase fluorescence in situ hybridisation (FISH) with satellite probes in fresh tumour material. RESULTS: The expression of proliferation associated antigen Ki67, using the monoclonal antibody MIB-1, and proliferating cell nuclear antigen (PCNA), using the antibody PC10, was found to be significantly higher in malignant versus benign liver tumours. Neither Ki67 nor PCNA expression were independent prognostic parameters. However, there was a tendency for a worse outcome (survival < 12 months) for patients with a high MIB-1 labelling index (> 20%) compared with patients having the same tumour stage and a low MIB-1 index. Aneusomy for chromosomes 1 and 8 was demonstrated by FISH in malignant tumours (six of seven hepatocellular carcinomas, four of five cholangiocellular carcinomas) but not in benign tumours (none of nine) or non-neoplastic liver (none of nine). CONCLUSION: Both the determination of the proliferating cell fraction and FISH analysis are useful for distinguishing hepatocellular carcinoma from liver cell adenoma or focal nodular hyperplasia; high fractions of proliferating cells are predictive of an early relapse.