Histiocytic sarcoma: PET-CT evaluation of a rare entity. Ann Nucl Med. 2008;22:715-717. [PMID: 18982475 DOI: 10.1007/s12149-008-0175-7]

18FDG PET/MRI in Histiocytic Sarcoma of the Spinal Canal

Histiocytic sarcoma is a malignant neoplasm of mature histiocytes that rarely involves the central nervous system. A 49-year-old man presenting with a mass filling the lumbar spinal canal underwent 18F-FDG PET/MRI. Fused PET/MRI images showed intense FDG uptake in the mass, as well as uptake in the cerebellopontine angle and cervical lymph nodes. Biopsy of the spinal lesion showed histiocytic sarcoma. This is the rare case report of PET/MRI performed for histiocytic sarcoma demonstrating changes in FDG uptake during chemotherapy. This case highlights the utility of PET imaging for evaluating the extent of lesions and treatment efficacy for histiocytic sarcoma.

Lymph node recurrence and re-excision after primary tumor resection of a histiocytic sarcoma of duodenal origin: a case report

BACKGROUND

Histiocytic sarcoma is a rare malignant tumor that is similar in characteristics to a mature histiocyte/macrophage and is a relatively new disease entity. In approximately one-third of cases, the site of origin is a lymph node; development from the gastrointestinal tract, spleen, soft tissue, and skin has further been reported. The tumor characteristics are not well-understood as reports on its clinical presentation and treatment are limited. We report a case of duodenal primary histiocytic sarcoma.

CASE PRESENTATION

An elevated lesion in the second part of the duodenum was detected in a 70-year-old woman during routine examination using upper gastrointestinal tract endoscopy. Blood biochemistry findings were normal for tumor markers. No abnormal findings were observed in the blood count and biochemical examination. Upper gastrointestinal endoscopy revealed a 20-mm elevated lesion with a slight depression in the center, opposite to the papilla of the descending duodenum. The biopsy showed erosions of the mucosal epithelium and inflammatory cell infiltration, but no evidence of malignancy. Ultrasound-guided endoscopy revealed an ischemic tumor of submucosal origin, and bowel biopsy suggested a histiocytic sarcoma. Distant metastasis and lymph node enlargement were absent on abdominal sonography, computed tomography, and magnetic resonance imaging. Duodenal segmental resection was performed. Immunostaining of the excised lesion was positive for CD68, CD163, CD4, CD5, CD15, and CD45 and negative for CD1a, CD21, CD34, MPO, and S-100 protein. Ki-67 positivity was approximately 20%. Based on these findings, the diagnosis of histiocytic sarcoma was confirmed. Ten months after the surgery, a lymph node recurrence in the dorsum of the pancreatic uncus was observed. No evidence of recurrence was found in any other part; hence, we performed pancreaticoduodenectomy. Pathological findings of the excised lymph node confirmed the recurrence of histiocytic sarcoma in the lymph node.

CONCLUSIONS

This is the first reported case of a duodenal primary histiocytic sarcoma with recurrence in the lymph node after the primary resection. The patient was treated for recurrence by lymph node excision and pancreaticoduodenectomy.

New onset headache caused by histiocytic sarcoma of the spinal cord and leptomeninges: a case report

Background

Headache due to raised intracranial pressure is rarely caused by spinal lesions. We describe a patient with primary histiocytic sarcoma who presented with a new onset headache with features of raised intracranial pressure and subtle signs of cauda equina syndrome due to predominant lower spinal cord infiltration and minimal intracranial involvement.

Case

A previously well 54-year-old man presented with a 2-month history of new onset headache with features of raised intracranial pressure. Progression of lower limb weakness was delayed and mild with diagnostic delay resulting from the primary presentation with headache leading to an initial focus on cerebral pathology. Subsequent investigations revealed a previously unreported presentation of primary histiocytic sarcoma infiltrating the cauda equina causing raised intracranial pressure headache.

Conclusion

This case highlights the importance of a broad search in the investigation of new onset raised intracranial pressure headache, including imaging of the lower spinal cord. Primary histiocytic sarcoma should be considered in the differential diagnosis of this rare syndrome.

Histiocytic sarcoma arising from a lymph node: a diagnostic conundrum

Histiocytic Sarcoma (HS) is extremely rare, with only a few hundred cases reported in the literature. The majority of patients present with symptoms due to unifocal or multifocal extra-nodal disease. Less than 20% of these cases show solitary involvement of a lymph node. We report a case of a solitary HS in a 53-year-old woman presenting with a 2.7-cm right groin mass arising from an inguinal lymph node. The initial cytologic examination of the tissue showed a high-grade spindle-shaped morphology with high-grade mitotic activity. A high-grade sarcoma was initially considered considering the absence of normal lymphoid aggregate and the presence of high-grade cytologic features in the cells. To evaluate the tumor in its entirety, the mass was surgically excised. A histological examination of the tumor showed focal rimming of the lymphoid tissue at the periphery and a centrally located stellate necrotic focus. The tumor cells had an epithelioid to spindle cell morphology along with large uniform nuclei and prominent nucleoli. A high mitotic index was present. Immunohistochemistry (IHC) stains showed strong positivity for CD68, CD163, and Vimentin, and were weakly positive for SMA and CD45. Based on the histologic and clinical examination, a diagnosis of HS was made. Multiple malignancies can mimic HS histopathology and the rarity of this tumor makes the diagnosis more challenging. No fine-needle aspiration (FNA) criteria for its diagnosis have been recognized. Herein, we report a rare case of an isolated HS involving a lymph node which resembled high-grade sarcoma on the FNA biopsy to raise awareness among our surgical pathologist colleagues.

Histiocytosis and Neoplasms of Macrophage-Dendritic Cell Lineages: Multimodality Imaging with Emphasis on PET/CT

Histiocytosis is a rare inflammatory process characterized by pathologic infiltration and accumulation of cells derived from the monocytic lineage in normal tissue. It encompasses more than 100 different subtypes of disorders that were recently classified into five main groups: (a) Langerhans-related histiocytosis, (b) Rosai-Dorfman histiocytosis, (c) cutaneous and mucocutaneous histiocytosis, (d) malignant histiocytosis, and (e) hemophagocytic lymphohistiocytosis and macrophage activation syndrome. Langerhans cell histiocytosis is the most common histiocytic disorder. Less common types include Erdheim-Chester disease, Rosai-Dorfman disease, adult and juvenile xanthogranuloma, necrobiotic xanthogranuloma, histiocytic sarcoma, interdigitating dendritic cell sarcoma, Langerhans cell sarcoma, and hemophagocytic lymphohistiocytosis. Although the pathogenesis of these disorders may be attributable to mutations in the oncogenic driver, recent discoveries have shown that inflammation and fibrosis secondary to mutated histiocytes, rather than a proliferative cell mechanism, result in manifestation of the disease. Diagnosis, which relies on a multidisciplinary approach, is challenging and often delayed because clinical findings are nonspecific and may mimic malignant processes at radiologic evaluation. Compared with conventional imaging, PET/CT allows detection of the increased metabolic activity in histiocytes. Diagnostic algorithms for histiocytic disorders should include functional imaging with fluorine 18 (¹⁸F) fluorodeoxyglucose (FDG) PET/CT, which provides a comprehensive whole-body evaluation of their potential involvement with multiple organ systems and allows monitoring of therapeutic response. The most recent revised classification, pathophysiologic and clinical manifestations, sites of involvement, and imaging features of histiocytosis are described in this review and a multimodality approach is used, with emphasis on ¹⁸F-FDG PET/CT evaluation. ^©RSNA, 2021.

Thrombocytopenia with multiple splenic lesions - histiocytic sarcoma of the spleen without splenomegaly: A case report

BACKGROUND

Histiocytic sarcoma (HS) of the spleen is reported to be a rare and lethal disease. The clinicopathological features of splenic HS have not been well described. The objective of this paper is to describe the diagnosis and treatment of a case of this rare disease and provide a review of the literature.

CASE SUMMARY

In this article, we discuss the case of a 40-year-old Hispanic female who presented with progressive thrombocytopenia and multiple hypoechoic lesions in the spleen without splenomegaly. Positron emission tomography-computed tomography showed increased activity in cervical lymph nodes, as well as multiple bone and splenic lesions with positive uptake. Two bone marrow biopsies and fine-needle aspiration of the cervical lymph node were inconclusive. Laparoscopic splenectomy was performed, and gross examination showed a 110.1 g spleen with multiple rubbery, nodular lesions within the subcapsular sinus and splenic parenchyma. The microscopic findings showed multinodular histiocyte proliferation with atypia and multilobulated nuclei, which were positive for CD163, CD4, and CD68 by immunohistochemical analysis. The final pathologic diagnosis was difficult and was found to be low-grade HS of the spleen, after consultations with two renowned hematopathology institutions. At the patient’s five-month follow-up visit, her bone marrow metastasis had progressed. She is waiting to be enrolled in a clinical trial.

CONCLUSION

Pathologic diagnosis of splenic HS can be challenging. Low-grade differentiation may be associated with a slow progressive disease.

Enhanced CT and FDG PET/CT in Histiocytic Sarcoma of the Pericardium

Histiocytic sarcoma is an extremely rare and aggressive malignant neoplasm of presumed hematopoietic origin. Lymph nodes are the most common sites of involvement. A variety of extranodal sites can be involved, particularly the gastrointestinal tract, soft tissue, skin, and spleen. Radiologic findings of histiocytic sarcoma have been rarely reported. We present a case with histiocytic sarcoma in pericardium, which is an unusual site. Enhanced chest CT showed remarkable enhancement of the tumor. On FDG PET/CT, the tumor showed intense FDG uptake.

Primary Orbital Histiocytic Sarcoma in a Child Successfully Treated With Multiagent Chemotherapy

Histiocytic sarcoma (HS), a malignant proliferation of mature tissue histiocytes presenting with single or multifocal extranodal tumors, is rarely seen in children. Primary orbital HS has never been reported in a child. Disseminated disease to the bone marrow typically has an aggressive course and poor prognosis. There is no consensus currently on the optimal therapeutic approach for HS. We present the case of a 2-year-old girl with orbital HS with likely bone marrow involvement treated successfully with multiagent chemotherapy, now in complete remission and disease free 3.5 years from end of therapy.

Insufficiency of bone scintigraphy in vertebral lesions of langerhans cell histiocytosis compared to f-18 fluorodeoxyglucose positron emission tomography/computed tomography and diagnostic computed tomography

Langerhans cell histiocytosis (LCH) is a benign disorder related to the histiocytes which can infiltrate bone tissue. The most effective method for demonstrating severity of this disease is PET/CT and bone scintigraphy might show bone lesions. We present a seventeen year old male patient with disseminated LCH presented with exophtalmos and having multiple vertebral lesions which were identified by F-18 FDG PET/CT scan and diagnostic CT but not in the bone scintigraphy.

Histiocytic sarcoma

A 59-year-old white woman, SC, after being treated for pneumonia, presented with an increase in the size of lymph nodes. The immunohistochemical examination diagnosed histiocytic sarcoma. Relapse occurred 12 months after starting chemotherapy. The patient evolved with febrile neutropenia, septic shock and death.

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.

Histiocytic sarcoma involving lymph nodes: imaging appearance on gallium-67 and F-18 FDG PET/CT

This report of an 82-year-old man who presented with a 3-week history of an enlarging left axillary mass and mild fevers, highlights the usefulness of both gallium-67 and F-18 FDG PET/CT imaging in the staging of histiocytic sarcoma. While PET/CT was superior in determining the extent of the disease, gallium can be used to help stage the disease in centers where PET/CT is not available.

Tc 99m bone scan and fluorodeoxyglucose positron emission tomography in evaluation of disseminated langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare histiocytic disorder in which pathological langerhans cells accumulate in a variety of organs. Manifestations may include lung infiltrates, lymph node involvements, bone lesions, hepatic, hematopoietic and endocrine dysfunctions. In this case report we present fluorine-18 positron emission tomography (F-18 PET/CT) and bone scintigraphy findings of a 18-year-old male patient with disseminated LCH, mimicking multiple hypermetabolic metastatic lesions. Clinicians should be aware that LCH infiltrations can be seen as intense uptake and to differentiate infiltrations from other metastatic intense uptake with fluorodeoxyglucose PET/CT and bone scintigraphy, clinical and laboratory findings should be kept in mind.

[A case of extranodal histiocytic sarcoma of stomach mimicking gastric adenocarcinoma]

Histiocytic sarcoma is a rare malignant neoplasm that originates from a histiocytic hematopoietic lineage characterized by histiocytic differentiation and its corresponding immunophenotypic features. Patients with histiocytic sarcoma usually have a poor prognosis due to its aggressive clinical behavior. Here we report a rare case of extranodal histiocytic sarcoma of the stomach which was confirmed through immunohistochemical staining. A 71-year- old man was presented with epigastric pain. Gastroscopy, abdominal CT, and EUS revealed a mass located on the posterior wall of upper body and fundus of the stomach. Grossly, grayish white solid masses were seen extending down to the submucosal layer. Microscopically, the tumor cells had eosinophilic cytoplasm, abundant vacuole, and mitosis. Immunohistochemical staining revealed that the tumor cells were positive for LCA, CD68, and lysozyme. Early detection and accurate diagnosis of this rare neoplasm is important because it can make a great difference in prognostic outcomes. To make an accurate and definitive diagnosis, immunohistochemical staining is essential in the confirmation of histiocytic origin.

Aggressive sporadic histiocytic sarcoma with immunoglobulin heavy chain gene rearrangement and t(14;18)

Histiocytic sarcoma (HS) is a rare but aggressive malignant neoplasm of histiocytic lineage with a poor prognosis. Immunohistochemically, the neoplastic cells are positive for CD163, CD68, and lysozyme, and negative for B and T cell markers. However, molecular studies on the origin of the neoplastic cells remain inconclusive. A 54-year-old woman was admitted to our hospital because of painful swelling of the left knee. Examination revealed generalized lymphadenopathy and splenomegaly. HS was diagnosed according to morphologic and immunohistochemical features observed on biopsy of the left inguinal lymph node. The tumor demonstrated a clonal immunoglobulin heavy chain gene rearrangement and a clonal cytogenetic abnormality including t(14;18) which was confirmed by fluorescence in situ hybridization analysis showing the IgH/BCL2 fusion gene. The neoplastic cells were negative for PAX5, a B cell associated transcription factor, and positive for CEBPβ, a transcription factor mediating macrophage and myeloid differentiation. Positron emission tomography showed disseminated areas of increased 18F-fluorodeoxyglucose uptake in multiple lymph nodes, the liver, spleen, both lungs, both kidneys, and many bony sites. The patient received localized irradiation therapy followed by chemotherapy, she failed to respond and died of the disease progression. The case findings suggest lineage promiscuity or plasticity related to the pathogenesis of HS.