Granulocytic sarcoma of the small intestine preceding acute myelomonocytic leukemia with abnormal eosinophils and inv(16)

Myeloid sarcoma and pathological fracture: a case report and review of literature

Myeloid sarcoma is a rare clinical entity that presents as an isolated proliferation of leukemic cells, concurrently with or at relapse of acute myeloid leukemia (AML), myelodysplastic syndromes/neoplasms (MDS), chronic myeloid leukemia (CML), and myeloproliferative neoplasm (MPN). Myeloid sarcoma disrupts the normal architecture of its surrounding tissues. When it forms in long bones, it can cause their pathological fracture. We recently experienced a rare case of MDS presenting with myeloid sarcoma in the femur that eventually resulted in its pathological fracture. Detailed chromosomal analysis of the bone marrow cells suggested emergence of myeloid sarcoma during the fast-paced progression of MDS just after acquiring trisomy 22. A comprehensive review of previous cases of myeloid sarcoma-associated pathological fracture indicated possible involvement of structural rearrangements of chromosomes 9 and 22. Management of myeloid sarcoma should continue to improve, and clinicians should note that myeloid sarcoma with specific chromosomal alterations needs extra medical attention to prevent pathological fracture.

Gastrointestinal Myeloid Sarcoma a Case Presentation and Review of the Literature

Myeloid sarcomas can be detected in up to 30% of acute myeloid leukemia cases or occur de-novo without bone marrow involvement. The most frequent localization of myeloid sarcomas in the abdominal cavity is the small intestine, and gastric presentations are infrequent, frequently misdiagnosed, and a high level of suspicion should exist when the characteristic histomorphology features are present. The current review features a case report with gastric presentation of myeloid sarcoma in a patient with a diagnosis of acute myeloid leukemia with trisomy 8. In addition, a review of the literature of intestinal-type myeloid sarcomas shows that less than 15% of these cases have been reported in the stomach. The most common molecular aberrancy detected in intestinal myeloid sarcomas is the fusion protein CBFB-MYH11. A review of several large studies demonstrates that the presence of myeloid sarcoma does not constitute an independent prognostic factor. The therapeutic approach will be tailored to the specific genetic abnormalities present, and systemic chemotherapy with hematopoietic stem cell transplant is the most efficient strategy.

Myeloid Sarcoma With CBFB-MYH11 Fusion (inv(16) or t(16;16)) Prevails in the Abdomen

OBJECTIVES

Myeloid sarcoma with CBFB-MYH11 fusion may be enriched in abdominal sites. The clinicopathologic features of 11 cases are reported.

METHODS

We collected clinical features, morphology, immunophenotype, and bone marrow (BM) involvement of myeloid sarcoma cases with CBFB-MYH11 fusion.

RESULTS

Eleven of 29 total myeloid sarcoma cases were CBFB-MYH11 positive and all 11 involved abdominal sites. The blastic infiltrate was associated with eosinophils in four of 11 cases and plasmacytoid dendritic cell (pDC) nodules in four of six cases. CD34, CD117, and myeloperoxidase were expressed in eight of nine, 10 of 10, and 10 of 10 cases, respectively. Ten of 10 cases showed no BM involvement.

CONCLUSIONS

Our current series, combined with a literature review, identifies a compelling series of 31 (94%) of 33 cases of myeloid sarcoma with CBFB-MYH11 fusion showing a marked predilection for abdominal sites. In addition, the lack of obvious associated eosinophils, presence of pDC nodules, and lack of concurrent BM involvement suggest that "myeloid sarcoma with CBFB-MYH11 fusion" may represent a unique phenomenon.

Educational Case: Myeloid Sarcoma: A Subtype of Acute Myeloid Leukemia

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Myeloid Sarcoma

Hematological malignancies can manifest as extramedullary soft tissue masses in relatively rare cases. The rarity of it causes a diagnostic and therapeutic challenge. One of the rarest manifestations is myeloid sarcoma (MS). MS develops as part of acute myeloid leukemia, myeloproliferative neoplasm, or myelodysplastic syndrome or at relapse, especially following allogeneic hematopoietic stem cell transplant. The tumor displays high myeloperoxidase expression, hence the color green, and is called chloroma. It most commonly appears in lymph nodes, skin and soft tissues, bone, testes, gastrointestinal tract, and peritoneum. Immunohistochemistry shows CD68-KP1 as the most commonly expressed marker, then myeloperoxidase, CD117, CD99, CD68/PG-M1, lysozyme, CD34, terminal deoxynucleotidyl transferase, CD56, CD61, CD30, glycophorin A, and CD4. Different chromosomal abnormalities including MLL rearrangement, t(8; 21), monosomy 7, trisomy 8, trisomy 11, trisomy 4, inversion (16), monosomy 16,16q deletion, 5q deletion, and 20q deletion were reported. Most of the literature about MS are case reports and small retrospective studies, thus there is limited clinical knowledge of the cases and their presentation and management plans. Here, we provide a review of what has been reported in the literature about MS in the light of our experiences.

Leukemia in gastrointestinal organs as cause of treatment failure: 378 cases analyzed

Leukemia growing as tumors in gastrointestinal organs is an under-investigated cause of treatment failure and death. These present with symptoms often mistaken for common toxicities but may grow large before symptoms. To synthesize experience available only in case reports, 378 were analyzed. Invasive and metastatic behavior typical of solid GI tumors was revealed even when marrow was uninvolved. Within 3 months of diagnosis, 33% had died, 47% within 1 year. Survivals of 4 to 18 years after involvement suggest cure is possible. Evidence is presented that combined local and systemic therapy has successfully treated GI leukemic tumors when identified early.

Isolated duodenal myeloid sarcoma associated with the CBFβ/MYH11 fusion gene followed by acute myeloid leukemia progression: A case report and literature review

Myeloid sarcoma (MS) is a rare disease that presents as an extramedullary tumorous mass of immature myeloid precursors. The majority of MS are identified in acute myeloid leukemia (AML) patients and rarely present as a primary isolated MS without AML. In addition, inversion of chromosome 16 [inv(16)] and the CBFβ/MYH11 fusion gene are rarely associated with MS. The current study reports a female patient with an isolated duodenal MS, who developed AML-M4 associated with the CBFβ/MYH11 fusion gene and 48,XX,inv(16),+13,+22. A review of previously reported cases of isolated MS with the CBFβ/MYH11 fusion gene was also performed. Isolated MS with the CBFβ/MYH11 fusion gene was often observed in abdominal lesions, with the intestinal tract being the predominantly involved site. In addition, patients with isolated MS with the CBFβ/MYH11 fusion exhibited a high risk of developing systemic AML. The diagnosis of isolated MS may be particularly challenging and, therefore, determining the optimal standard treatment for isolated MS is required.

Granulocytic sarcoma of abdomen in acute myeloid leukemia patient with inv(16) and t(6;17) abnormal chromosome: case report and review of literature

Granulocytic sarcoma (GS) is composed of immature granulocytic precursors and is usually found in acute myeloid leukemia (AML) patients with t(8;21). Inv(16) is rarely associated with GS comparing with t(8;21) leukemia. Here we describe an abdominal GS patient in AML-M2 with acquired translocation between chromosomes 6 and 17 and inv (16). We have also summarized 20 reported GS cases with inv(16) and found that chloroma was most often found in abdominal lesions. Intestine maybe a tissue specific target for the expression of inv(16) leukemia. Complete physical examination and molecular diagnosis are necessary for AML patients to benefit from the diagnosis and therapeutic strategy.

Extensive involvement of the gastrointestinal tract by a de novo presentation of the monoblastic type of myeloid sarcoma: a case report of a rare entity that is often misdiagnosed

We present the first known case of the monoblastic type of myeloid sarcoma (also known as extramedullary myeloid tumor, chloroma, and granulocytic sarcoma) with diffuse involvement of the gastrointestinal tract. The patient originally presented with diarrhea and crampy abdominal discomfort. Endoscopically, the disease showed a diffuse inflammatory process mimicking a number of benign conditions, such as inflammatory bowel disease and autoimmune enteropathy. Sequential biopsies of the upper and lower gastrointestinal tract showed a diffuse infiltrate of increasingly atypical cells. The disease progressed to systemic involvement, including widespread lymphadenopathy, splenomegaly, and pulmonary deposits; the patient died 13 months after the development of initial symptoms. The immunohistochemical and histologic profiles of this case are diagnostic of the monoblastic type of myeloid sarcoma.

Myeloid sarcoma: extramedullary manifestation of myeloid disorders

Myeloid sarcoma (MS), also termed extramedullary acute myeloid leukemia, extramedullary myeloid tumor, and granulocytic sarcoma or chloroma, is a rare manifestation that is characterized by the occurrence of 1 or more tumor myeloid masses occurring at an extramedullary site. The wide spectrum of this disorder and the conditions that it overlaps diagnostically were well reflected in the 25 cases submitted to the Society for Hematopathology/European Association for Haematopathology Workshop held in Indianapolis, IN, in November 2007. This review, on the one hand, focuses on the definition and most recent achievements on the pathobiology of MS, and on the other, also in the light of the revised World Health Organization classification, summarizes the main features of a representative series of this condition aiming to provide readers a useful document for daily practice.

Granulocytic sarcoma: 32 cases and review of the literature

Thirty-two cases of granulocytic sarcoma (GS) are reported in this paper. Age range was from 16 - 70 years. GS was accompanied by AML in 13 cases, ALL (My+) in one case, CML in 11 cases and MDS in two cases. GS was diagnosed simultaneously with leukemia in five cases and preceded the leukemia in eight. Lymph node and soft tissue were the most commonly detected localizations. Seven cases had first been diagnosed as NHL. Histopathologically blastic, immature and mature variants were found in 11, nine and 11 cases respectively and overall survival was shortest in the blastic type. Myeloperoxidase and lysozyme were found to be positive in 30 and 24 cases respectively. Therapy was radiation in five cases and surgery in three. Systemic chemotherapy was given to the cases. The clinical outcome of the patients after the diagnosis of GS was poor. GS is a unique entity; prognosis is poor but it is important to detect the signaling pathways associated with migration of myeloid cells to the extra-medullary tissues. The critical factors for detecting this interesting tumor are to be aware of this disease, cooperation between clinician and pathologist and the application of special stains to detect the myeloid origin.

t(5;12)(q13;p13) in acute myeloid leukemia with preceding granulocytic sarcoma

A 56-year-old woman was brought to the emergency room with gum swelling and pain. Biopsy of the gingiva revealed sheet-like proliferation of myeloperoxidase and CD45-positive large cells, and she was diagnosed with granulocytic sarcoma. Two years later, bone marrow involvement of granulocytic sarcoma was suspected. Her chromosome study repeatedly revealed a 46,XX,t(5;12)(q13;p13) karyotype. Case reports of t(5;12)(q13;p13) are extremely rare in the literature. To our knowledge, this is the first report of t(5;12)(q13;p13) in a patient with acute myelogenous leukemia with preceding granulocytic sarcoma.

Granulocytic sarcoma of bowel: CT findings

PURPOSE

To evaluate retrospectively the computed tomographic (CT) findings of granulocytic sarcoma of the bowel.

MATERIALS AND METHODS

The institutional review boards of all participating institutions approved this study and waived the requirement for informed consent. CT scans were retrospectively reviewed in eight patients (seven men, one woman; age range, 23-71 years; mean age, 46 years) with pathologically proved granulocytic sarcoma of the small and/or large bowel. CT findings were evaluated with regard to the sites, morphologic characteristics, and contrast material enhancement patterns of the lesions, along with other ancillary findings (ie, peritoneal and mesenteric infiltration, ascites, lymphadenopathy, bowel perforation, and obstruction).

RESULTS

Eight patients had a total of 13 lesions in the bowel (of which eight were pathologically proved), involving the duodenum (n=1), jejunum (n=2), ileum (n=5), sigmoid colon (n=1), and rectum (n=4); multifocal bowel lesions were noted in four patients. The lesion varied in shape, with wall thickening alone in three of 13 lesions, an intraluminal polypoid mass in four, an exophytic mass in one, and a combination of findings in five. Contrast material enhancement, relative to the back musculature, showed isoattenuation in seven lesions, hyperattenuation in four, and hypoattenuation in two. Five of eight patients had multiple peritoneal masses with diffuse mesenteric or peritoneal infiltration. Ascites was present in six of eight patients; lymphadenopathy (especially in the mesentery), in five; bowel perforation, in two; and bowel obstruction, in one.

CONCLUSION

Granulocytic sarcoma of the bowel is characterized by variability in shape and contrast enhancement and has a high predilection for mesenteric and peritoneal spread.

Myeloid sarcoma: clinico-pathologic, phenotypic and cytogenetic analysis of 92 adult patients

Myeloid sarcoma (MS) is a rare neoplasm whose knowledge is largely based on case reports and/or technically dated contributions. Ninety-two MSs in adulthood with clinical data available were evaluated both morphologically and immunohistochemically. Seventy-four cases were also studied by fluorescent in situ hybridization on tissue sections and/or conventional karyotyping on bone marrow or peripheral blood. Histologically, 50% of the tumors were of the blastic type, 43.5% either monoblastic or myelomonocytic and 6.5% corresponded to different histotypes. CD68/KP1 was the most commonly expressed marker (100%), followed by myeloperoxidase (83.6%), CD117 (80.4%), CD99 (54.3%), CD68/PG-M1 (51%), CD34 (43.4%), terminal-deoxy-nucleotidyl-transferase (31.5%), CD56 (13%), CD61/linker for activation of T cells (2.2%), CD30 (2.2%) and CD4 (1.1%). Foci of plasmacytoid monocyte differentiation were observed in intestinal cases carrying inv16. Chromosomal aberrations were detected in about 54% of cases: monosomy 7(10.8%), trisomy 8(10.4%) and mixed lineage leukemia-splitting (8.5%) were the commonest abnormalities, whereas t(8;21) was rare (2.2%). The behavior was dramatic irrespective of presentation, age, sex, phenotype and cytogenetics. Most if not all, long survivors received bone-marrow transplantation. The present report expands the spectrum of our knowledge showing that MS has frequent monoblastic/myelomonocytic differentiation, displays distinctive phenotypic profile, carries chromosomal aberrations other than t(8;21), and requires supra-maximal therapy.

Granulocytic sarcoma of the small intestine

Granulocytic sarcoma is an extramedullary tumor of myeloblasts and/or immature myeloid cells, which can develop at any anatomic site and is often a forerunner to the development of acute myelogenous leukemia. Granulocytic sarcoma of the gastrointestinal tract most frequently involves the small intestine and most often presents with abdominal pain and obstruction. Pathologists must consider granulocytic sarcoma in any mass of unknown origin with a diffusely infiltrating population of tumor cells, as the diagnosis is often initially unrecognized, especially in nonleukemic patients. Multiple ancillary modalities are available to assist pathologists in making the correct diagnosis so that appropriate therapy can be initiated.

Granulocytic sarcoma of mesentery in acute myeloid leukemia with CBFB/MYH11 fusion gene but not inv(16) chromosome: Case report and review of literature

Granulocytic sarcoma (GS) is a rare extra-medullary tumor and usually involves the skin, soft tissue, and lymph nodes. GS is found in 8% of acute myeloid leukemia (AML) patients, especially patients with t(8;21)AML. It has been suggested that GS is a poor prognostic factor in t(8;21)AML. Compared to t(8;21)AML, GS is rare in cases of inv(16)AML. Thus, the characteristics of inv(16) with GS are not well understood. Here, we describe a patient with AML and mesentery GS. The chromosomal analysis was normal, but molecular analysis detected the CBFB/MYH11 fusion gene in the blasts. A complete remission was achieved with standard induction therapy followed by high-dose cytarabine consolidation. We have also summarized 12 reported cases of inv(16)AML with GS and found that GS was commonly found in abdominal lesions. These observations suggest that when abdominal GS is diagnosed, an analysis of the CBFB/MYH11 fusion gene is necessary to make an appropriate decision regarding treatment options, even if no chromosomal abnormalities are found.

Clinico-pathological characteristics of myeloid sarcoma at diagnosis and during follow-up: report of 12 cases from a single institution

The aim of this study was to describe the presenting features, the frequency and outcome of myeloid sarcoma (MS) diagnosed in our Institution from January 1995 to December 2000. Twelve MS were seen and the frequency account for only 2% of all acute myeloid leukemia (AML) patients observed in our department in the same period. Median age was 45 years (range: 4-84). All had been initially misdiagnosed as malignant lymphoma (ML) and a median of 2.9 months (range: 1-6) elapsed between the misdiagnosis and the correct of MS, effectuated in our department. At that time, a bone marrow examination revealed a myelodysplastic condition in seven patients, an infiltration by blast cells >30% in two patients, and normal features in the other three. In the non-leukemic patients a median of 5 months (range: 2-44 months) elapsed between the diagnosis of MS and acute leukemia. In all, 10 patients received intensive treatment. A total of seven patients (70%) achieved MS complete remission (CR). Patients who presented isolated skin localization and received only radiotherapy, obtained a MS-CR, but subsequently developed AML. Only in patients who were treated within 4 months from the initial ML diagnosis we achieved complete remission of both MS and leukemia, whereas in patients who were treated after this time, we obtained a complete disappearance of MS without response at the bone-marrow level, irrespectively of the specific therapy regimen. Median survival time from MS diagnosis was 7 months (range: 1-49 months), and only one patient is still alive, 49 months after bone marrow transplantation. Our data stress the importance of an accurate and prompt identification of this rare form of AML, and suggest that, even in patients with isolated MS, the early administration of AML-like intensive chemotherapy followed by bone marrow transplantation might reduce the risk of subsequently developing systemic disease.

Eosinophilic gastroenteritis or eosinophilic chloroma?

Granulocytic sarcoma of the small intestine preceding or as the presenting feature of acute myelogenous leukemia with chromosome 16 abnormalities has been observed in at least 4 patients. We report the case of a patient initially diagnosed with eosinophilic gastroenteritis, responding to corticosteroid treatment for 21 months and eventually transforming into an acute myelogenous leukemia with eosinophilia (M4Eo variant).

Myeloid sarcoma: clinical and morphologic criteria useful for diagnosis

Extramedullary accumulation of myeloblasts or immature myeloid cells form tumors called myeloid sarcoma in the WHO classification. Such tumors develop in lymphoid organs, bone (skull, orbit, etc.), skin, soft tissue, various mucosae and organs, and the CNS. They may precede or occur concurrently with acute myeloid leukemia, or reveal blastic transformation of chronic myeloproliferative disorders or myelodysplastic syndromes. They may also reveal relapses in treated patients. They are constituted by a diffuse infiltrate made up of medium-to-large cells. The cells are difficult to identify. Imprints are very useful. Immunohistochemistry can help diagnose and distinguish four variants: granulocytic myeloperoxidase (MPO+, CD 68+ [KP1+/-, PGM1-] lysozyme+, CD 34+/-), monoblastic (MPO-, CD 68+, [KP1+, PGM1+] lysozyme+, CD 34-), myelomonoblastic (MPO-, CD 68+, [KP1+, PGM1+] lysozyme+, CD 34-), or megakaryoblastic (positivity for factor VIII, CD 61, CD 31). Immunohistochemistry sometimes demonstrates expression of CD 43, CD 7, CD 79a, and CD 56 (particularly the monoblastic variant with t[8;21]). Recently the demonstration of CD 99 and CD 117, which can now be done on paraffin sections, may be useful to identify blasts of granulocytic origin. The diagnosis is missed in about 50% of cases when immunohistochemistry is not used. Patients with myeloid sarcomas should be treated in the same way as patients with acute myeloblastic leukemia. Disease progression and prognosis are similar for the two conditions.

Granulocytic sarcoma of the small intestine with CBFbeta/MYH11 fusion gene: report of an aleukaemic case and review of the literature

Granulocytic sarcomas (GS) are rare extramedullary tumours composed of immature myeloid cells. Inversion of chromosome 16 [inv(16)] is a cytogenetic marker for M4Eo subtype of acute myeloid leukaemia (AML). The possibility of an association between the development of granulocytic sarcoma of the small intestine (GSSI) and the M4Eo subtype of AML was suggested in nine previous case reports. Here we report an aleukaemic case of GSSI with inv(16) and its molecular equivalent, the CBFbeta/MYH11 fusion gene, detected by reverse transcriptase-polymerase chain reaction (RT-PCR), that after treatment with conventional AML chemotherapy followed by autologous bone marrow transplantation, achieved complete haematological and molecular remission on bone marrow examination. After chemotherapy, a thickened ileum wall positive for CBFbeta/MYH11 on tumour mass samples was still observed on computed tomography (CT) studies, raising the question of residual GS representing a reservoir of malignant cells. This case demonstrates the critical need of multidisciplinary diagnosis and follow-up of this entity combining immunopathologic, cytogenetic and molecular studies, reinforcing the potentiality of risk-adapted therapy strategies, as it is increasingly claimed for patients with overt AML.

[Granulocytic sarcoma (chloroma) of small bowel: an unfrequent cause of intestinal obstruction]

Granulocytic sarcoma or chloroma is a malignant extra medullar tumor, based on inmature myeloid cells. It usually emerges as a secondary manifestation of acute myeloid leukemia. Chloromas are scarcely diagnosed in patiens without hematological malignances, either peripheral or medullar, and are thus frequently misdiagnosed for other tumors. In these patients, further development of acute leukemia seems to stand as a rule. Small bowel location of these tumors has hardly been reported. A case of granulocytic sarcoma in a non-leukemic at time of diagnosis patient is reported therein. Medical literature is briefly reviewed.

Myelodysplasia presenting as granulocytic sarcoma of mediastinum causing superior vena cava syndrome

Granulocytic sarcomas (GS) are extramedullary tumor masses of immature myeloid cells, most frequently associated with hematological disorders including acute myeloid leukemia (AML), chronic myelogenous leukemia (CML), and myelodysplastic syndrome (MDS). Recent interest has centered upon the possible biologic properties that enable theses myeloid cells to adhere to tissues and establish a tumor mass. GS presenting as a mediastinal mass is relatively infrequent, and more uncommon is presentation with the superior vena cava syndrome. We present one such case and review some of the available literature.

Granulocytic sarcoma of the pancreas: a report of two cases and literature review

Granulocytic sarcomas (GS) are extramedullary tumour masses of immature myeloid cells, also known as chloroma and extramedullary myeloid cell tumour. These neoplasms usually occur simultaneously with, or follow the onset of acute myeloid leukaemia (AML). Rarely, they are the first manifestation of AML. GS may also be the first sign of transformation to AML in patients with chronic myeloproliferative disorders and myelodysplastic syndromes. GS have been reported to occur in a variety of tissues, but presentation as an abdominal mass and, in particular, infiltration of the pancreas is rare. We report two cases of pancreatic GS, review the literature, and discuss recent insights into the basic biological properties of these rare tumours.

Granulocytic sarcoma of the jejunum: a rare cause of small bowel obstruction

We report the case of a 40-yr-old man presenting with symptoms of small bowel obstruction. Small bowel x-rays revealed a stricture of the mid-jejunum. Push enteroscopy found a polypoid mass at 1 meter of the ligament of Treitz. Histopathological examination of the biopsy and surgical specimens showed a diffuse infiltrate of the mucosa made of medium to large cells, which were stained on immunohistochemistry by the leucocyte marker CD45 and the histiocyte/monocyte marker CD68 but were negative for the B and T cell markers. Cytological examination of the ascitic fluid revealed many myelobasts with cytoplasmic Auer rods and positive myeloperoxidase staining. There was no evidence of blood or bone marrow involvement suggestive of acute leukemia or myeloproliferative disorders. These findings were consistent with the diagnosis of preleukemic granulocytic sarcoma (or chloroma). Chemotherapy led to complete remission, but 21 months later the patient developed an acute myeloid leukemia. He died from aspergillus pneumonitis, 10 months after bone marrow allograft. Preleukemic granulocytic sarcoma of the small bowel is a rare condition and its diagnosis is usually not easy, requiring histochemical or immunohistochemical studies. Most cases have progressed to acute myeloid leukemia.

Granulocytic sarcoma with translocation (9;11)(p22;q23): two cases

Granulocytic sarcomas are localized deposits of myeloid leukemia cells that may precede or occur concurrently with disseminated disease. In either event, the origins of the cells comprising the malignancy are the same. Published reports of granulocytic sarcomas have described, in the majority of cases, a morphology typical of AML-M2 and the presence of the t(8;21)(q22;q21) typical of that FAB type. In a smaller number of cases, the inv(16)(p13q22) characteristic of AML-M4 has been recorded in cells with a myelomonocytic appearance. We report two patients with granulocytic sarcomas showing monocytic morphology in which the malignant cells showed t(9;11)(p22;q23) typical of AML-M5. This abnormality is seen in up to 7% of childhood AML, but has not previously been reported in granulocytic sarcoma. The detection of this cytogenetic abnormality facilitated the precise characterization of the malignant cells and selection of the most appropriate therapy, emphasizing the value of cytogenetic analysis in cases of granulocytic sarcoma.

Case report: granulocytic sarcoma of the small bowel--a rare presentation of leukaemia

Granulocytic sarcoma (GS) is a local tumour mass that is associated with acute leukaemia. It may present simultaneously with leukaemia or may rarely predate it. The following case demonstrates the radiological features of GS and the importance of its recognition in the treatment.

Granulocytic sarcomas of small intestine and brain are associated with acute myelomonocytic leukaemia with abnormal eosinophils and inversion of chromosome 16

We report two cases of acute myelomonocytic leukaemia with abnormal eosinophils (M4Eo) in which the presenting feature was small bowel obstruction. We suggest there is a unique clinicopathological association between small intestine involvement with leukaemia and the M4Eo subtype. Central nervous system involvement by myeloblastoma occurred in one of the two cases which is a recognised feature of M4Eo and should necessitate prophylaxis with intrathecal therapy. Inversion of chromosome 16 which is a cytogenetic marker for M4Eo was demonstrable in one of the two cases.

Cytogenetic analysis of a granulocytic sarcoma in a patient without systemic leukaemia

Granulocytic sarcoma is a rare complication of leukaemia. Occasionally it presents before the development of systemic leukaemia when diagnosis may be difficult. A case of granulocytic sarcoma occurring in a patient with no overt evidence of leukaemia, but in whom cytogenetic analysis of the bone marrow showed a clonal t(12;13) translocation, is reported. Cytogenetic analysis of tissues in this disease may indicate evidence of systemic disease before overt morphological changes.

Is trisomy 22 in acute myeloid leukemia a primary abnormality or only a secondary change associated with inversion 16?

In an attempt to confirm the existence of acute myeloid leukemia (AML) with trisomy 22, we studied three patients in whom trisomy 22 imposed as the sole karyotype abnormality. After revision of the karyotypes, however, we were able to identify an inv(16) as the important primary abnormality in all of them. Based on this experience, we investigated whether at least some of the 17 AML cases with trisomy 22 reported so far might possibly have been misinterpreted. Interestingly, ten out of 16 evaluable cases were classified as M4, some of them with bone marrow eosinophilia. As in cases with inv(16), only few metaphases contained trisomy 22. Furthermore, in at least two out of the only four published karyotypes of cases with trisomy 22, an inv(16) is evident and in the other two cases it cannot be ruled out. We therefore believe that at least some of the trisomy 22 cases mentioned in the literature are in fact only secondary changes occurring in AML with an inv(16) and suggest that future reports of AML with trisomy 22 as a specific primary abnormality can only be accepted as such if inv(16) has been excluded with appropriate methods.