Case Of Primary Histiocytic Sarcoma Research Articles

THU107 A Case Of Primary Histiocytic Sarcoma Of Pituitary Gland Presenting With Central Diabetes Insipidus

Abstract Disclosure: S. Ahn: None. Y. Kim: None. Y. Cho: None. D. Seo: None. S. Kim: None. J. Cho: None. S. Choi: None. K. Kim: None. E. Kim: None. S. Hong: None. Introduction: Histiocytic sarcoma is a rare and aggressive hematopoietic neoplasm derived from non-Langerhans histiocytic cells of the monocyte/macrophage system. Here, we reported the first case of primary histiocytic sarcoma involving pituitary gland. Methods: Medical records were reviewed. Results: A 53 years old Korean men presented with general weakness, polydipsia, polyuria, and abnormal thyroid function test suspicious for secondary hypothyroidism. Laboratory examinations showed growth hormone deficiency, hypogonadotropic hypogonadism, and central diabetes insipidus. The magnetic resonance imaging showed a well-enhanced mass involving entire posterior pituitary gland with stalk thickening. The biopsy of pituitary mass was identified as a malignant tumor consistent with histiocytic sarcoma. This malignant tumor inoperably increased within a short duration and hormone deficiency such as secondary hypothyroidism and adrenal insufficiency additionally developed. Therefore, the patient started radiation therapy with desmopressin, levothyroxine, and hydrocortisone replacement. Conclusion: The biopsy is not regarded as the mandatory procedure for diagnosing patients with central diabetes insipidus with posterior pituitary lesion since in many cases, this is the result of hypophysitis. However, since there is still the possibility of primary malignancy and metastasis involving pituitary gland, an appropriate decision for performing biopsy should be made according to the patient’s clinical situations. Presentation: Thursday, June 15, 2023

A case of primary histiocytic sarcoma arising from a neck lymph node.

Histiocytic sarcoma (HS) is an aggressive and rare hematological malignancy. Its treatment has not been established, and most patients die within 2years of diagnosis. Resection can provide a favorable prognosis for solitary lesions. We present the case of an 80-year-old Japanese man with HS. He presented a history of a slow-growing painless mass in the lower part of his right jaw. Ultrasonography showed a swollen lymph node in the vicinity of the right submandibular gland. Contrast-enhanced computed tomography revealed a heterogeneous, low-contrast mass on the right of the neck. Magnetic resonance imaging revealed a heterogeneously enhanced mass in gadolinium-enhanced T1-weighted images. The fine needle biopsy showed spindle-shaped cells and HS was suspected. Fluorodeoxyglucose positron emission tomography revealed uptake by the tumor alone. The patient underwent right upper neck dissection and resection of the submandibular salivary glands. No postoperative adjuvant treatment was administered, but 2-year survival was achieved. Histopathological examination showed proliferation of large, pleomorphic atypical cells without differentiation into lymphocytes, which proved their differentiation into histiocytes. A bone marrow biopsy showed no evidence of monocytic leukemia. Thus, a diagnosis of HS was made. With local treatment alone, our patient achieved long-term survival, maintaining his quality of life.

Genomic profiling of primary histiocytic sarcoma reveals two molecular subgroups.

Histiocytic sarcoma is a rare malignant neoplasm that may occur de novo or in the context of a previous hematologic malignancy or mediastinal germ cell tumor. Here, we performed whole exome sequencing and RNA-sequencing (RNA-Seq) on 21 archival cases of primary histiocytic sarcoma. We identified a high number of genetic alterations within the RAS/RAF/MAPK pathway in 21 of 21 cases, with alterations in NF1 (6 of 21), MAP2K1 (5 of 21), PTPN11 (4 of 21), BRAF (4 of 21), KRAS (4 of 21), NRAS (1 of 21), and LZTR1 (1 of 21), including single cases with homozygous deletion of NF1, high-level amplification of PTPN11, and a novel TTYH3-BRAF fusion. Concurrent NF1 and PTPN11 mutations were present in 3 of 21 cases, and 5 of 7 cases with alterations in NF1 and/or PTPN11 had disease involving the gastrointestinal tract. Following unsupervised clustering of gene expression data, cases with NF1 and/or PTPN11 abnormalities formed a distinct tumor subgroup. A subset of NF1/PTPN11 wild-type cases had frequent mutations in B-cell lymphoma associated genes and/or clonal IG gene rearrangements. Our findings expand the current understanding of the molecular pathogenesis of this rare tumor and suggest the existence of a distinct subtype of primary histiocytic sarcoma characterized by NF1/PTPN11 alterations with predilection for the gastrointestinal tract.

Imaging features of primary extranodal histiocytic sarcoma: report of two cases and a review of the literature

Histiocytic sarcoma is an extremely rare and aggressive malignancy of bone marrow origin that occurs in lymph nodes, skin, and the gastrointestinal tract. We report on the imaging features of two cases of primary histiocytic sarcoma, one in the retroperitoneum causing a tumor–bowel fistula and another with primary bone involvement.

A Case of Primary Histiocytic Sarcoma Arising from Thyroid Gland

Histiocytic sarcoma (HS) is an extremely rare true histiocytic malignancy. We report a case of HS arising from thyroid gland in a 69 year-old man. Following subtotal thyroidectomy, a histopathologic, immunohistologic, and genotypic examination revealed HS. This tumor was composed of large spindle or round epithelioid cells with abundant eosinophilic cytoplasm. The neoplastic cells were positive for macrophage-associated antigen CD68, CD163, and lysozymes, as well as CD45, HLA- DR, DP, DQ, and S100, most consistent with a diagnosis of HS. The BIOMED-2 multiplex PCR analysis showed polyclonal B- and T-cell populations. To our knowledge, this is the first report of a rare entity HS involving thyroid gland using a comprehensive immunophenotyping panel including CD163 as well as molecular studies to establish the true histiocytic nature of these lesions.