Cytokeratin-positive interstitial cell neoplasm: a case report and classification issues

Cytokeratin-positive interstitial reticulum cell (CIRC) tumor in the lymph node: a case report of the transformation from the epithelioid cell type to the spindle cell type

Background

Cytokeratin-positive interstitial reticulum cells (CIRCs), which are a subgroup of fibroblastic reticular cells (FRCs), are known to be present in the lymph nodes. There have been only a few cases of tumors derived from CIRCs.

Case presentation

We have reported a new case involving a CIRC tumor in a 75-year-old man and reviewed the literature. The resected mediastinal lymph nodes showed epithelial-like proliferation of large atypical round and polygonal epithelioid cells. The tumor cells expressed CK8, CK18, CAM5.2, AE1/AE3, epithelial membrane antigen, vimentin, fascin, and some FRC markers, which is consistent with the diagnosis of a CIRC tumor. Following chemotherapy, the CIRC tumor was observed to have responded very well and became difficult to confirm on imaging, but a small cell lung carcinoma developed 12 months later. Chemoradiotherapy was performed, but the patient passed away 29 months after the initial diagnosis. The autopsy revealed the recurrence of the CIRC tumor, residual small cell lung carcinoma, and a very small latent carcinoma of the prostate. The relapsed CIRC tumor cells had a spindle shape; they were highly pleomorphic and had invaded the superior vena cava.

Conclusion

We first reported autopsy findings of CIRC tumors and demonstrated the transformation of the tumor from the epithelioid cell type to the spindle cell type.

Spinal Cord Compression Caused by Fibroblastic Reticular Cell Tumor (FRCT) Originating from Thoracic Spine

BACKGROUND

The authors present the first reported case of a fibroblastic reticular cell tumor (FRCT) presenting with spinal cord compression. FRCTs are the rarest subset of dendritic cell tumors, a specific group of hematologic malignancies. FRCTs reportedly behave similar to low-grade sarcomas as opposed to malignant tumors.

CASE DESCRIPTION

A 45-year-old female patient presented with a 2-and-a-half week history of a flu-like illness and 1 week history of lower limb imbalance. Magnetic resonance imaging revealed an extradural lesion at T3/4 compressing the spinal cord. Initially, the patient was presumed to have metastatic spinal cord compression, and she underwent a decompressive thoracic laminectomy with debulking of the lesion with follow-up adjuvant radiotherapy. However, histology identified a unique primary FRCT originating from spine, not secondary metastatic spinal cord compression. There were no histologically aggressive features likely contributing to the favorable outcome following surgery and adjuvant radiotherapy. Her postoperative recovery was unremarkable, and she recovered fully.

CONCLUSIONS

Although rare, we report the first case of FRCT originating in the spine causing spinal cord compression. The clinical presentation of the case, histologic features of FRCT, and the treatment options are reviewed.

An Unusual Bump on the Head: Intracranial and Extracranial Cytokeratin-Positive Interstitial Reticular Cell Tumor

BACKGROUND

We describe a cytokeratin positive interstitial reticulum cell tumor (CPIRCT) as the cause of a large and defacing scalp tumor. Clinically these tumors manifest as progressive, painless swelling. Treatment usually consists of surgery with or without irradiation; chemotherapy is applied in metastatic disease.

CASE DESCRIPTION

A patient was referred after attempted removal of a large bump on the head. The tumor was initially noted about 12 months earlier. Assuming a benign lipoma, resection without prior imaging was attempted. During surgery, the underlying bone was found to be profoundly destroyed. Cranial magnetic resonance imaging revealed a large mass with an extracranial and intracranial component. Subsequent extensive resection finally led to the diagnosis of CPIRCT.

CONCLUSIONS

Most CPIRCTs manifest as progressive palpable or visible masses. Radical excision is usually the mainstay of treatment, although there is no generally accepted treatment strategy. A needle biopsy might not be diagnostic and can complicate future curative surgery. Especially in fast-growing lesions, imaging studies should be considered before surgery. Their potential recurrence and metastatic spread render CPIRCTs an interdisciplinary challenge and highlight the need for long-term follow-up.

Fibroblastic reticular cell tumor of the breast: A case report and review of the literature

Fibroblastic reticular cells (FBRCs) are basic mesenchymal cells that belong to the dendritic cell family. Primary extranodal FBRC tumor (FRCT) cases are rare, with only 19 cases reported in the literature thus far. However, none of these cases originated in the breast tissue. To the best of our knowledge, the present study reported the first FRCT case of the breast in a 57-year-old woman. The patient complained of a painless mass that was located in the right breast and was ~3.5×2.5 cm in size. The patient underwent modified radical mastectomy subsequent to the diagnosis of FRCT after analysis of the lumpectomy specimen. Pathological examination revealed that the tumor was mainly composed of oval and spindle cells, and was infiltrated with lymphocytes and plasma cells. The tumor cells were immunoreactive for vimentin and negative for CD21, CD35 and S-100 protein. Six axillary lymph nodes were found to have been involved. Following surgery, the patient received four cycles of mesna, doxorubicin, ifosfamide and dacarbazine regimen chemotherapy (70 mg adriamycin day 1; 2.0 g ifosfamided days 1-3; 0.4 g dacarbazine day 1-3), which cycled every 21 days. The patient was uneventfully followed-up for 20 months following chemotherapy. In conclusion, the present study reported what appeared to be the first case of primary breast FRCT. The diagnosis, treatment and prognosis details presented in this study will help improve the diagnosis of the disease.

Cytokeratin-positive interstitial reticulum cell tumor: recognition of a potential "in situ" pattern

Cytokeratin-positive interstitial reticulum cell (CIRC) tumor is a very rare accessory cell neoplasm of lymphoid organs derived from fibroblastic reticulum cells, which originate from mesenchymal stem cells. We describe the histologic, immunophenotypical, and molecular features of a CIRC tumor in a 67-year-old woman who underwent hysterectomy, bilateral adnexectomy, and pelvic lymphadenectomy for endometrial carcinoma. An enlarged pelvic node contained circumscribed neoplastic infiltrates in perifollicular and interfollicular areas consisting of large cells arranged in a reticular pattern with nuclear atypia, atypical mitoses, and apoptosis, but without glandular architecture or disruption of overall architecture. The atypical infiltrate coexpressed cytokeratin and vimentin, partially CD68, CD163, and lysozyme, but lacked markers of endometrial carcinoma, consistent with a diagnosis of CIRC tumor. Despite the obviously neoplastic cytological features, immunostains revealed the circumscribed and noninvasive pattern of the lesion, possibly representing an early "in situ" stage of CIRC tumor.

Cytokeratin-positive fibroblastic reticular cell tumor with follicular dendritic cell features: a case report and review of the literature

Fibroblastic reticular cell (FRC) neoplasms, which are one of the histiocyte tumor types, are very rare. Here we report a cytokeratin (CK)-positive FRC neoplasm having features of follicular dendritic cells in a 54-year-old woman with right axillary lymph node swelling. The resected lymph node showed multiple nodular aggregations simulating and replacing normal follicles. The tumor cells had a uniform, large and oval to polygonal shape, abundant cytoplasm, and various sizes of nuclei with central eosinophilic nucleoli and coarse nuclear chromatin. They were positive for CK AE1/AE3+CAM5.2, CK7, tenascin C, l-caldesomone, and CD21, weakly positive for S100, and negative for CD1a. Ultrastructurally, the tumor cells had long interdigitating microvillus-like cell processes and oval to elongated vesicular nuclei. In addition, the intercellular spaces contained accumulations of collagen, and some tumor cells had desmosomal-like junctions. These findings suggest that the present case is a CK-positive FRC tumor with follicular dendritic cell features.

A Rare Case of Cytokeratin-Positive Interstitial Reticulum Cell Sarcoma and Review of the Entity

The tumors of dendritic/reticulum cells constitutes the rarest tumors affecting the lymphoid tissues. Among them tumors derived from fibroblastic reticular cells (FBRCs) are very rare, and those of cytokeratin (CK)-positive interstitial reticulum cells (CIRCs) origin are even more rare. These tumors can be easily misdiagnosed as tumors of other dendritic cells, myofibroblastic tumors or even metastatic poorly differentiated carcinomas. Less than twenty such cases have been reported in the literature till date. We present such a rare case of CIRC sarcoma in cervical lymph node of a 64-year-old man.

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.

Histiocytic and Dendritic Cell Neoplasms

This article reviews the features of dendritic cells (DCs) of myeloid-derived, plasmacytoid, and follicle-associated types and tumors of these cells, as well as myeloid sarcoma. The morphologic and immunophenotypic features in this group of neoplasms is featured, including mature neoplasms such as Langerhans cell histiocytosis, its malignant counterpart Langerhans cell sarcoma, and S100-negative histiocytic proliferations. More immature or precursor malignancies in this group include myeloid and monocytic leukemias presenting in extramedullary tissues as well as the newly codified blastic plasmacytoid dendritic cell neoplasm. Although likely not related histogenetically to myeloid-derived DCs, mesenchymal-type lymph node tumors including follicular dendritic cell and fibroblastic reticulum sarcomas are also discussed. All of these neoplasms can exhibit a range of immunophenotypic and morphologic features that underscore the plasticity of the non-neoplastic precursors from which they are derived.

Endothelial and virgultar cell formations in the mammalian lymph node sinus: endothelial differentiation morphotypes characterized by a special kind of junction (complexus adhaerens)

The lymph node sinus are channel structures of unquestionable importance in immunology and pathology, specifically in the filtering of the lymph, the transport and processing of antigens, the adhesion and migration of immune cells, and the spread of metastatic cancer cells. Our knowledge of the cell and molecular biology of the sinus-forming cells is still limited, and the origin and biological nature of these cells have long been a matter of debate. Here, we review the relevant literature and present our own experimental results, in particular concerning molecular markers of intercellular junctions and cell differentiation. We show that both the monolayer cells lining the sinus walls and the intraluminal virgultar cell meshwork are indeed different morphotypes of the same basic endothelial cell character, as demonstrated by the presence of a distinct spectrum of general and lymphatic endothelial markers, and we therefore refer to these cells as sinus endothelial/virgultar cells (SEVCs). These cells are connected by unique adhering junctions, termed complexus adhaerentes, characterized by the transmembrane glycoprotein VE-cadherin, combined with the desmosomal plaque protein desmoplakin, several adherens junction plaque proteins including alpha- and beta-catenin and p120 catenin, and components of the tight junction ensemble, specifically claudin-5 and JAM-A, and the plaque protein ZO-1. We show that complexus adhaerentes are involved in the tight three-dimensional integration of the virgultar network of SEVC processes along extracellular guidance structures composed of paracrystalline collagen bundle "stays". Overall, the SEVC system might be considered as a local and specific modification of the general lymphatic vasculature system. Finally, physiological and pathological alterations of the SEVC system will be presented, and the possible value of the molecular markers described in histological diagnoses of autochthonous lymph node tumors will be discussed.

So-called inflammatory myofibroblastic tumour: a proliferative lesion of fibroblastic reticulum cells?

The term inflammatory pseudotumour was originally used in a generic fashion for any lesion which simulated a neoplastic condition at a clinical, macroscopic and microscopic level but which was thought to have an inflammatory/reactive pathogenesis. In more recent times, the term has been employed in a more restrictive sense for a mass lesion characterized microscopically by the proliferation of a spindle cell component against a heavy inflammatory infiltrate of mixed composition but usually with a predominance of mature lymphocyte and plasma cells. The spindle cell component has generally been regarded as being of mesenchymal nature and having morphological and phenotypical features consistent with fibroblasts or myofibroblasts, the latter cell being clearly preferred over the former in the more resent reports. The term inflammatory myofibroblastic tumour (IMFT) is the one currently favoured, which proposes the myofibroblastic nature of the process. It is the purpose of this review to bring forth some evidence that the neoplastic spindle cell component of IMFT may be instead derived from the subtype of cells of the accessory immune system that have been variously called fibroblastic reticulum cells, myoid cells, and dictyocytes.