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A 12-year-old girl presented to us with an
asymptomatic, slowly increasing, abdominal mass of two-year duration. On
examination it was an 11 ´
10 cm firm, non-tender mass in left upper abdomen, fixed to the deep
fascia. There was no discoloration of overlying skin. There was no
significant lymphadenopathy. Ultrasound reported a solid, hypoechoic,
and septate mass in left side of abdomen causing bulging of abdominal
wall; liver and both kidneys were normal. Contrast enhanced CT scan
revealed a large lobulated heterodense mass lesion with hypodense areas
suggestive of necrosis, in left upper abdomen, displacing the stomach
and small bowel loops posteriorly, with indentation of anterior wall of
stomach, transverse colon and descending colon. The anterior abdominal
wall was stretched over the mass with loss of intervening fat planes and
prominent vessels were seen in the vicinity of the lesion inferiorly.
Detailed workup for metastasis that included chest roentgenogram was
negative. Fine needle aspiration cytology of the mass was reported as
malignant mesenchymal tumor. Three cycles of neo-adjuvant chemotherapy
were given (VAC) at three weekly intervals with no significant reduction
in tumor size after initial minimal reduction and localization of the
mass. Repeat fine needle aspiration cytology was done to obtain a more
specific diagnosis; this was reported as a round cell tumor with focally
prominent perivascular survival pattern. Patient underwent wide surgical
excision of tumor. On exploration, there was a parietal mass adhered to
left lower ribs and diaphragm, with prominent vessels seen all around
it. Primary reconstruction of abdominal wall defect was possible with
the help of myoaponeurotic-fascial rotation flaps. The histopathology
report was hemangio-pericytoma (HPC) with occasional mitotic figures.
Surgical margins were free of tumor. Postoperative recovery was
uneventful. There has been no evidence of local recurrence or metastases
over the past 6 months.
HPC is an uncommon vascular tumor arising from
pericytes and known to occur in any part of the body and in all age
groups; only ten per cent of all HPC are found in children. It is a
tumor with relatively high malignant potential and often confused with
other soft tissue sarcomas such as hemangioendothe-lioma, vascular
leiomyoma, fibrous histio- cytoma, synovial sarcoma and mesenchymal
chondrosarcoma. Abdominal wall is rather an uncommon site for HPC in
children.
Conclusive diagnosis of HPC requires adherence to
strict histologic crieteria. HOC is characterized by a uniform
histologic picture consisting chiefly of thin walled, gaping, vascular
channels of varying caliber and densely packed tumor cells having oval
or elongated nuclei and an indistinct cytoplasm. The individual cells
are separated from one another by a dense meshwork of reticulin fibres
and from the lining endothelium of the vascular spaces by a basement
membrane(1). Hypercellularity, mitotic activity, anaplasia, sparse
reticulin network, necrosis and hemorr-hage are associated with more
malignant behavior. In general, more deeply placed tumors with a size of
more than 6.5 cm and a mitotic index of more than 4 mitoses per 10 HPF
tend to be more aggressive(2). Complete radical surgical excision is the
treatment of choice in all resectable HPC. Adjuvant chemo-therapy and
radiotherapy have been consi-dered for recurrent and metastatic
disease(3).
We conclude that although FNAC is an acceptable and
safe modality of diagnosis in pediatric oncology with its advantage of
not requiring hospitalization or anesthesia, it has its limitations in
diagnosing a few tumors like HPC.
Alpana Prasad,
*R.K. Saran,
Y.K. Sarin,
Department of Pediatric Surgery,
Maulana Azad Medical College and
Department of Pathology*,
G.B. Pant Hospital, New Delhi 110 002, India.
-
Enzinger FM, Smith BH. Hemangio-pericytoma; An
analysis of 106 cases. Hum Pathol 1976; 7: 61-82.
-
Craven JP, Terence MQ, Bolen JW, Raker EJ. Current
management and clinical outcome of hemangiopericytomas. Am J Surg 1992;
163: 490-493.
- Kumar R, Corbally M. Childhood hemangio-pericytoma. Med Pediatr
Oncol 1998; 30: 294-296.
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