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

A Fibroblastic Reticular Cell Tumour Arising in the Oral Cavity: A Case Report and Review of the Literature

BACKGROUND

Tumours of dendritic or histiocytic lineage are amongst the rarest tumours and probably account for < 1% of tumours affecting the lymph nodes or soft tissue. Because several of these entities were poorly recognised until recently, the true incidence is not determined.

METHODS

We present what we believe is the first reported case report of a fibroblastic reticular cell tumour arising in the oral cavity as well as reviewing the current literature regarding this rare subset of tumours.

RESULTS

We discuss the clinical and histopathological findings of our reported case and examine the literature regarding this entity. We discuss the key differential diagnoses to consider when making this diagnosis.

CONCLUSION

Histiocytic and dendritic cell derived tumours are exceptionally rare within the head and neck region although a number of these tumours have been reported within the oral cavity. We present what we believe is the first reported case of a fibroblastic reticular cell tumour arising within the oral cavity.

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.

Castleman's disease

Castleman's disease, a type of lymph node hyperplasia, usually occurs in the mediastinum and rarely presents in the cervical region as an asymptomatic solitary mass. Clinically, they are of two types-solitary and multi-centric. Most of the solitary types are asymptomatic with no associated symptoms, whereas the multi-centric type is associated with systemic symptoms and has a poor prognosis. Histologically, they can be classified as-Hyaline vascular, plasma cell, transitional and stromal rich type. We report a case of Castleman's disease involving the submandibular lymph node in a 75-year-old male patient whose definitive diagnosis was made only on histological examination. Isolated Castleman's disease of the submandibular node is rare and a thorough clinical and histological examination is necessary to rule out the systemic form of the disease and other diseases with manifestations as a cervical lymph node enlargement.