Cecal Mucosal Myxoma: The First Report of a New Type of Mesenchymal Colon Polyp

Small intestinal myxoma presented with bowel obstruction, a rare case report

INTRODUCTION

Myxomas are rare benign mesenchymal neoplasms and mostly occur in cardiac atrium and with lower prevalence, appear in sinonasal tract, gnathic bone, skin and joints. Benign primary tumors of the small intestine are quite unusual accounting about 3% of all the gastrointestinal tract neoplasms.

PRESENTATION OF CASE

In this report, we present a rare case of small intestinal myxoma in a 43-year-old man complicated by ileoileal intussusception causing bowel obstruction. The patient underwent segmental resection of small bowel and the histopathologic evaluation confirmed the diagnosis of small intestinal myxoma.

DISCUSSION

Among benign primary neoplasms of small bowel, Solitary intestinal myxomas are extremely rare mostly locate in submucosal layer of gastric, small bowel and rarely in cecum. To our knowledge only 9 cases of small bowel myxoma is reported in the literature so far.

CONCLUSION

This case report aware surgeons and pathologists about rare occurrence of intestinal myxomas as a differential diagnosis of intussusception.

A conjunctival myxoid stromal tumor (COMST) mimicking phlyctenulosis: A case report and brief review of the literature

Purpose

This is a case report of a patient with a conjunctival myxoid stromal tumor (COMST), mimicking a phlyctenulosis. Tumors of the conjunctiva and cornea occupy a large spectrum ranging from benign lesions of myxoma to aggressive, life-threatening malignancies. Phlyctenulosis and phlyctenular keratoconjunctivitis are hypersensitivity reactions to a foreign antigen.

Observations

A 64-year-old male presented with six-month history of non-painful lump in the conjunctiva of the left eye. It was a mobile, non-tender, non-ulcerated, non-hemorrhagic, non-pigmented lesion and was non-adherent to the sclera. The differential diagnosis of phlyctenulosis or a soft tissue tumor was considered. The lesion was completely excised. The microscopy showed an ill-defined hypocellular myxoid lesion composed of stellate and spindle-shaped cells with eosinophilic cytoplasm, containing round-ovoid and spindle-shaped nuclei with a vesicular chromatic pattern. The tumor cells were diffusely and strongly positive for vimentin and CD 34 and were negative for S100. The immunomorphological features were compatible with a conjunctival myxoid stromal tumor. Complete systemic evaluation excluded the possible association with systemic myxomas.

Conclusions and importance

Myxoid tumors of the conjunctiva are benign tumors, however, they can mimic other benign conditions like phlyctenulosis or more sinister lesions like malignant tumors. Therefore, it is important to do an excisional biopsy to ascertain the definitive pathology of an indeterminate conjunctival lesion. COMST may be the index presentation for the detection of previously undiagnosed myxoma syndromes. One such association is with cardiac myxomas, which can result in vascular embolic events. Therefore, it is important to do cardiac screening in all patients diagnosed with a COMST.

Plexiform fibromyxoma: Review of rare mesenchymal gastric neoplasm and its differential diagnosis

Plexiform fibromyxoma (PF) is a very rare mesenchymal neoplasm of the stomach that was first described in 2007 and was officially recognized as a subtype of gastric mesenchymal neoplasm by World Health Organization (WHO) in 2010. Histologically, PF is characterized by a plexiform growth of bland spindle to ovoid cells embedded in a myxoid stroma that is rich in small vessels. The lesion is usually paucicellular. While mucosal and vascular invasion have been documented, no metastasis or malignant transformation has been reported. Its pathogenesis is largely unknown and defining molecular alterations are not currently available. There are other mesenchymal tumors arising in the gastrointestinal tract that need to be differentiated from PF given their differing biologic behaviors and malignant potential. Histologic mimics with spindle cells include gastrointestinal stromal tumor, smooth muscle tumor, and nerve sheath tumor. Histologic mimics with myxoid stroma include myxoma and aggressive angiomyxoma. Molecular alterations that have been described in a subset of PF may be seen in gastroblastoma and malignant epithelioid tumor with glioma-associated oncogene homologue 1 (GLI1) rearrangement. The recent increase in publications on PF reflects growing recognition of this entity with expansion of clinical and pathologic findings in these cases. Herein we provide a review of PF in comparison to other mesenchymal tumors with histologic and molecular resemblance to raise the awareness of this enigmatic neoplasm. Also, we highlight the challenges pathologists face when the sample is small, or such rare entity is encountered intraoperatively.