Myeloid sarcoma and adenocarcinoma of the large bowel as collision tumors: a case report

First reported case of a collision tumor composed of pancreatic adenocarcinoma and retroperitoneal liposarcoma: a case report

BACKGROUND

Collision tumors are rare cases with two different tumor entities growing synchronously. While adenocarcinoma of the pancreas is the most common pancreatic tumor with an incidence of 10 per 100.000, retroperitoneal liposarcoma remains very rare. This is the first report of a collision tumor between these two tumor entities.

CASE PRESENTATION

Demographic details: The tumor was diagnosed in a 64 male Caucasian patient. Besides atrial fibrillation, arterial hypertension and a hypothyroidism there is no relevant medical history especially no history of cancer. Clinical details: During a routine check-up an unclassified tumor of the pancreatic tail was diagnosed. The lab showed no pathologies. Tumor markers were negative for carbohydrate antigen 19-9 and 72-4 (CA 19-9, CA 72-4) and carcinoembryonic antigen (CEA). Alpha-fetoprotein (AFP) and neuron specific enolase (NSE) were both elevated (AFP 97kU/l, (< 5,8kU/l) and NSE 30,0 μg/l (16,4 μg/l)). A computed tomography-guided core needle biopsy was performed which revealed a low-grade liposarcoma (G1). A CT scan showed no metastases. A surgical resection was recommended by the interdisciplinary tumor board.

INTERVENTIONS

A systematic left sided retroperitoneal compartment resection including en-bloc-left sided pancreatectomy, splenectomy, nephrectomy, hemicolectomy, adrenalectomy, partial gastrectomy and partial resection of the diaphragm was performed. Pathology revealed a collision tumor consisting of pancreatic adenocarcinoma that was classified pT3, pN2 (11/33 ece+) L1 V0 Pn0, R0; G2 [UICC Stage III] and a liposarcoma pT2, pN0 (0/33) L0 V0 Pn0, G1 [UICC Stage Ib]. The postoperative tumor board recommended an adjuvant chemotherapy with gemcitabine and capecitabine for the locally advanced pancreatic adenocarcinoma.

OUTCOME

At the latest follow-up (1 year after surgery) the patient was in good clinical condition and without evidence of tumor recurrence.

CONCLUSION

Collision tumors are rare and difficult to diagnose. This is the first description of a collision tumor composed of pancreatic adenocarcinoma and retroperitoneal liposarcoma. The reported case demonstrates that inconsistent diagnostic results (e.g. imaging and pathology) should raise suspicion concerning the diagnosis. Awareness of these rare cases might protect us from underdiagnosing patients and therefore leading to better patient care. There is evolving evidence that will lead to more personalized treatment options for somatic BRCA mutated pancreatic cancer.

Myeloid transformation of plasma cell myeloma: molecular evidence of clonal evolution revealed by next generation sequencing

Background

Plasma cell myeloma (PCM) is a neoplasm of terminally differentiated B lymphocytes with molecular heterogeneity. Although therapy-related myeloid neoplasms are common in plasma cell myeloma patients after chemotherapy, transdifferentiation of plasma cell myeloma into myeloid neoplasms has not been reported in literature. Here we report a very rare case of myeloid neoplasm transformed from plasma cell myeloma.

Case presentation

A 60-year-old man with a history of plasma cell myeloma with IGH-MAF gene rearrangement and RAS/RAF mutations developed multiple soft tissue lesions one year following melphalan-based chemotherapy and autologous stem cell transplant. Morphological and immunohistochemical characterization of the extramedullary disease demonstrated that the tumor cells were derived from the monocyte-macrophage lineage. Next generation sequencing (NGS) studies detected similar clonal aberrations in the diagnostic plasma cell population and post-therapy neoplastic cells, including IGH-MAF rearrangement, multiple genetic mutations in RAS signaling pathway proteins, and loss of tumor suppressor genes. Molecular genetic analysis also revealed unique genomic alterations in the transformed tumor cells, including gain of NF1 and loss of TRAF3.

Conclusion

To our knowledge, this is the first case of myeloid sarcoma transdifferentiated from plasma cell neoplasm. Our findings in this unique case suggest clonal evolution of plasma cell myeloma to myeloma neoplasm and the potential roles of abnormal RAS/RAF signaling pathway in lineage switch or transdifferentiation.

Myeloid sarcomas: a clinicopathologic study of 20 cases

Objective:

Myeloid sarcoma is a tumoral mass of mature or immature myeloid blasts in extramedullary anatomic locations. It can be seen de novo or in association with acute myeloid leukemia, myeloproliferative neoplasias, or myelodysplastic syndrome. Isolated myeloid sarcoma can be seen as a relapse in cases with allogenic bone marrow transplantation. Although it may involve any tissue in the body, the most common locations are skin, soft tissues, lymph nodes, and the gastrointestinal tract. Immunohistochemically, most cases show myelomonocytic or pure monoblastic differentiation. We reviewed the clinicopathological features of 20 cases of myeloid sarcoma diagnosed in our institute in view of the literature.

Materials and Methods:

The cases diagnosed between 2005 and 2012 at the Ankara University Faculty of Medicine, Department of Pathology, were selected. Clinicopathological findings including the age and sex of the patients; symptoms; anatomic location; accompanying hematological disease; and the morphological, immunohistochemical, and cytogenetic features of the cases were noted.

Results:

Sixteen of the patients were male and 4 were female. The median age at diagnosis was 47 years. The most commonly involved locations were the lymph nodes and skin. Immunohistochemically, eleven cases were of the myelomonocytic and 7 cases were of the myeloid phenotype, whereas 2 cases showed pure monoblastic differentiation. The median follow-up period for the 18 cases with known clinical data was 33 weeks. Five patients died of the disease in an average of 36 weeks.

Conclusion:

Myeloid sarcoma is a rare presentation of leukemias, myeloproliferative neoplasias, or myelodysplastic syndrome, composed of immature myelomonocytic cells in extramedullary tissues. It may present with variable morphological and phenotypic features, always creating a challenge in pathological diagnosis.