Ionized Calcium Binding Adaptor Molecule 1 (IBA1)

OBJECTIVES

Ionized calcium binding adaptor molecule 1 (IBA1), a marker of microglia/macrophages, has not been investigated in human hematopathologic contexts. We evaluated its expression in mature and immature neoplasms of monocytic/histiocytic and dendritic cell (DC) origin.

METHODS

Immunohistochemistry for IBA1, CD14, CD68, and CD163 was performed on a total of 114 cases, including a spectrum of monocytic/histiocytic and DC neoplasms (20 tissue based and 59 bone marrow based) and several nonhistiocytic/monocytic/DC neoplasms as control groups (15 tissue based and 20 bone marrow based).

RESULTS

IBA1 expression was observed in all types of mature tissue-based histiocytic/DC neoplasms (20/20) but not in the corresponding control group (0/15). In bone marrow-based cases, IBA1 was expressed in most acute myeloid leukemias (AMLs) with monocytic differentiation (48/53), both blastic plasmacytoid dendritic cell neoplasms (2/2), and all chronic myelomonocytic leukemias (4/4), while it was positive in only one nonmonocytic AML (1/15) and none of the acute lymphoblastic leukemias (0/5). Collectively, IBA1 showed much higher sensitivity and specificity (93.7%, 97.1%) compared with CD14 (65.4%, 88.2%), CD68 (74.4%, 74.2%), and CD163 (52.6%, 90.6%).

CONCLUSIONS

IBA1 is a novel, highly sensitive, and specific marker for diagnosing neoplasms of monocytic/histiocytic and DC origin.

Intra-Extracranial Primary Clear Cell Sarcoma: The First Report and Review of the Literature

BACKGROUND

Clear cell sarcoma (CCS) is a rare malignant soft tissue tumor with poor prognosis owing to metastasis and insensitive response to chemotherapy and radiotherapy.

METHODS

We first searched PubMed and Embase using the terms "clear cell sarcoma," "malignant melanoma of soft tissue," "head," and "neck." In the 15 articles selected for literature review, only 27% (4/15) of patients were diagnosed with primary CCS of the head. Pathologically, those tumors arose from either the scalp or the superficial temporal fascia, but none invaded the skull and brain. Next, the search was performed in the same database using the terms "clear cell sarcoma," "malignant melanoma of soft tissue," and "bone," and only 24 articles were selected.

RESULTS

In the case reported here, a 36-year-old woman was found to have a palpable mass located at the left temporal-occipital region, and surgical finding confirmed the invasion into the skull and the brain. The diagnosis of primary CCS was made because of the detection of t(12;22)(q13;q12) in >50% of tumor cells by fluorescence in situ hybridization, and metastasis to the lymph nodes and lungs was discovered by postoperative positron emission tomography-computed tomography.

CONCLUSIONS

To the best of our knowledge, this is the first case of primary central nervous system CCS. Primary CCS may involve the skull and should be one of the differential diagnoses for intra-extracranial communicating tumors. Further research on biological characteristics and molecular targeted therapy of CCS are needed to improve its poor prognosis.

Primary follicular dendritic cell sarcoma of the urinary bladder: the first case report and potential diagnostic pitfalls

BACKGROUND

Extranodal follicular dendritic cell sarcoma (FDCS) is a very rare malignancy with a variable clinical course. It is often not considered and has the potential to result in a misdiagnosis of other common sarcomas or sarcomatoid carcinomas. This is particularly true with the preoperative biopsy specimen, in which the tissue sample is often small.

CASE PRESENTATION

A case of FDCS in a 63-year-old woman, arising in the urinary bladder, a previously unreported site, is described. The patient presented with the typical clinical symptoms of a bladder cancer, and the morphology of the tumor was similar to a lymphoepithelioma-like carcinoma, ultimately resulting in it being misdiagnosed. The patient received radical cystectomy, without further radiotherapy or chemotherapy. Two years after operation, a metastatic tumor to the lung was found. The mass of the right main bronchus lumen was frozen and resected through bronchoscopy, and radiotherapy was performed. The patient has lived with the tumor since then.

CONCLUSIONS

This paper presents the first FDCS occurring in the urinary bladder with metastasis to the lung and emphasizes potential diagnostic pitfalls.

Follicular dendritic cell sarcoma treated with a variety of chemotherapy

Follicular dendritic cell sarcoma (FDCS) is a very rare malignant tumor derived from follicular dendritic cells. Radical resection is the standard therapy for patients with local disease, but an optimal chemotherapy regimen has not been determined for unresectable disease. We report our experience of an FDCS patient with multiorgan involvement. In the present case, disease was only located in the pancreas initially and radical resection was performed. Multiple metastasis developed after the treatment and several factors that indicated a poor prognosis were observed. The present case had a very poor prognostic disease but survived for a long time with a good performance status because of the multiple chemotherapy regimens, which follow therapeutic strategies for malignant lymphoma and soft tissue sarcoma. As far as we know, this is the first study reporting the indication of bendamustine for FDCS patients.

Spontaneous regression of interdigitating dendritic sarcoma in a patient with concurrent small lymphocytic lymphoma

Interdigitating dendritic cell sarcoma (IDCS) is a rare tumour; only seven cases of IDCS associated with chronic lymphocytic leucaemia/small lymphocytic lymphoma (CLL/SLL) have been reported. We present the case of a 60-year-old man who presented with fevers, night sweats and significant unintentional weight loss. Investigations led to a diagnosis of synchronous SLL and IDCS. Subsequent fluorodeoxyglucose (FDG) positron emission tomography CT (PET-CT) imaging revealed an unusual clinical course with spontaneously resolving highly metabolic lesions. After 42 months of follow-up, the patient remains free of clinical symptoms and evidence of IDCS.

Follicular dendritic cell sarcoma of the stomach: case report and review of the literature

Follicular dendritic cell sarcoma (fdcs) is a rare entity, often presenting a diagnostic challenge for both the pathologist and the clinician. It accounts for only 0.4% of soft-tissue sarcomas, and its underlying causes are largely unknown. Most of these tumours occur in lymph nodes, and extranodal involvement is uncommon. In the gastrointestinal tract, fdcs is extremely rare. Here, we report a case of primary fdcs originating in the stomach. Upon review of the literature, we identified only 2 additional cases of fdcs presenting as a primary stomach tumour. Given the rarity of this tumour in gastrointestinal sites and the lack of consensus on treatment, evaluation of this entity must continue.

Dendritic cell sarcoma: a pooled analysis including 462 cases with presentation of our case series

Dendritic cell tumors are extremely rare and current knowledge on these tumors is limited. The characteristics of three dendritic cell sarcoma subtypes and their optimal treatment approaches are not fully clarified. We aimed to make a systematic review of the literature and enrich the current data with five new cases. Pooled analysis of 462 reported cases revealed that the tumor had no age, gender or racial predilection. Our analysis suggests that the young age, advanced stage, intraabdominal involvement and unfavorable histological features (i.e. large tumor size, absence of lymphoplasmacytic infiltration, coagulative necrosis, high mitotic count) may predict poor prognosis. Subtypes of this tumor have different clinical behaviors with interdigitating dendritic cell sarcoma being the most aggressive form. In general, surgery is the most effective treatment modality and adjuvant radiotherapy has no significant effect on overall survival of patients. The role of chemotherapy for the management of advanced disease is controversial.