# A case report of histiocytic sarcoma mimicking acute pericarditis

## TL;DR

A rare case of histiocytic sarcoma in the heart was misdiagnosed as pericarditis, and treatment with chemotherapy led to severe complications and death.

## Contribution

This case report highlights the diagnostic and therapeutic challenges of histiocytic sarcoma involving the heart.

## Key findings

- Histiocytic sarcoma involving the heart is extremely rare and difficult to diagnose.
- Neoadjuvant chemotherapy regimens for this condition lack consensus and can lead to severe complications.
- Surgical excision is preferred when feasible, but not always possible.

## Abstract

Pericardial masses are rare disease requiring incremental diagnostic workout to differentiate benignant from malignant lesions. No solid evidence exists regarding their management, and their treatment requires a case-by-case evaluation.

A 54-year-old man was diagnosed with a pericardial mass. After performing cardiac magnetic resonance and computed tomography, a high suspicion of malignancy was raised. Positron emission tomography and pericardial biopsy confirmed the presence of a primary histiocytic sarcoma. After multidisciplinary evaluation, the mass was considered not suitable for surgical removal, and a neoadjuvant chemotherapy strategy was started. The first chemotherapy regimen—consisting of cyclophosphamide, doxorubicin, etoposide, vincristine, and methylprednisolone—was not effective. Therefore, a second, more aggressive, regimen consisting of cladribine, cytarabine, granulocyte-colony stimulating factor, and mitoxantrone was started. Following the first cycle, the patient developed bone marrow aplasia and septic shock leading to the exitus.

Histiocytic sarcomas primarily involving the heart are extremely rare. Surgical excision represents the first therapeutic choice when feasible. When not pursuable, a neoadjuvant therapy is preferred, although no consensus exists regarding the chemotherapy regimen.