Introduction:

     PPNETs are peripheral primitive neuroectodermal   tumors and a group of highly cellular primitive round cell   neoplasm’s which occur extra-cranially in soft tissues and bones and are derived from embryonal neural crest cells. Askin tumors are malignant cell tumors   of   neuroepithelial origin appearing in the soft tissues of chest wall, occasionally in bone or rarely in the periphery of the lung (1).

Case report:

A 2.5-years old girl who was known case of PNET referred to our hospital with dyspnea and tachypnea. In physical examination, she had pallor appearance, pulse rate was 130/minutes and BP was 90/60 mm Hg. We decided to start chemotherapy regime. The chest X-ray revealed bilateral opacity (fig. 2). After consulting with general surgeon, the bilateral chest-tubes were inserted and 200cc   blood was drained.  The hemoglobin was 4.6gr/dl and platelet count 259000 cell/µl, PT: 12 and PTT: 25 sec.

In the plural tap, total cell count was 2110 cell/ml, neut:7, lymph:8, RBC:2095, LDH: 1974, protein:5/2gr/dl GLU:40mg/dl and concomitant BS was 65 mg/dl. Cytopathology of pleural fluid did not show malignant cells. Hemotherapy with packed Red Blood cells transfusion was done. She remained in hospital and received conservative management with broad spectrum antibiotic. After a few days the chest–tubes were clamped and then removed. Our patient discharged with good condition. The patient had been diagnosed 9 months ago with symptoms such as fever, anorexia, weight loss, gait disturbance and limping.

In Para-clinical study and MRI of spinal cord and vertebra there was evidence of mass at postero lateral part of spinal canal which impressed cord at level T2 through T4 vertebral bodies (fig. 3).  The biopsy showed malignant round cell tumor compatible with primary nuroectodermal tumor (PNET) (fig. 1) and immunohistochemistry was positive for mic2 (CD99) and chromogranin A.

Discussion:

Ewing’s family of tumors (EFTs) include Ewing’s tumor of bone (ETB or Ewing’s sarcoma of bone), extraosseous Ewing’s (EOE), primitive neuroectodermal tumor (PNET or peripheral primitive neuroepithelioma), and Askin’s tumor (PNET of the chest wall) (2). Studies using imunohistochemical markers, cytogenetics , molecular genetics, and tissue culture  indicate that these tumors are derived from the same primordial stem cell (3,4).   Hemothorax is a well-recognized sequel of chest trauma, ruptured aortic aneurysm, inadvertent vessel damage, pulmonary infarct, intrapulmonary arteriovenous fistula, neoplasm, etc. (1).

The diagnosis of a hemothorax can be made only by thoracentesis (5). Inadequate removal of blood in extensive hemothorax may lead to substantial restrictive disease secondary to organization of fibrin (5).Primitive Neuroectodermal Tumors (PNET) are malignant small cells neoplasm mainly occurring in children but can occur at any age (6).

PNETs have a common histological appearance of densely cellular masses of
uniform small oval or round cells (7).

The symptomatology of the Peripheral Primitive Neuroectodermal Tumors is
related to size and their location (1).

In our case, the location of the tumor was in vertebra (T2-T4) and symptoms were gait disturbance, limping, and fever.

Drugs that were used for chemotherapy in our patient were vincristin, actinomycin-D, cyclophosphamide, adriamycin, and alternatively ifosfamide and etoposid. The adverse effect of hemothorax has not been reported in drug references (8,9)
We did not find any residue of cancer as a cause of hemothorax, and the hemothorax was not related to side effects of chemotherapy, infection and trauma. Therefore, PNET should be included as a cause of children hemothorax.