John R. Goldblum
An 8-year-old Caucasian female had a recent history of a 15-pound weight loss, nausea, vomiting and diarrhea. Upon
evaluation, the patient was found to have a 9-cm pelvic mass, which was excised.
Cheryl M. Coffin
Primary Children's Medical Center
Salt Lake City, Utah
A two-day-old boy underwent resection of a congenital tumor from the left thigh. The tumor was 4.5 cm in diameter,
and the overlying skin was erythematous.
Sharon W. Weiss
Emory University Hospital
The patient was a 15 year old male who presented with a 3 month history of a painful right thigh mass. No other
associated laboratory abnormalities were noted. Following an incisional biopsy a more extensive excision was
performed. The gross specimen consisted of skin, subcutaneous tissue and an underlying portion of sartorius
muscle. The latter was involved by a partially hemorrhagic infiltrating lesion. Your sections are taken from the
David M. Parham
Arkansas Children's Research Hospital
Little Rock, Arkansas
This 14 year-old girl presented with persistent cough, fatigue, weight loss, anorexia, and headache of 2 months
duration. Laboratory results included a hemoglobin of 106 g/L, leukocyte count of 8.8 X 109/L, platelet count of
335 X 109/L, serum lactate dehydrogenase of 7975 u/L, and a serum uric acid of 416 ?mol/L. Computed tomography of
the chest and abdomen revealed a large, left-sided, pleural-based soft tissue mass associated with a large pleural
effusion, compression of the left lung, and right-sided mediastinal displacement was found on computed tomography.
Retroperitoneal adenopathy involving the celiac axis and associated with massive ascites was noted in the abdomen.
Cytologic examination of the pleural fluid revealed malignant undifferentiated cells (Figure 1). No metaphases
were obtained on cytogenetic studies. Bone marrow examination was negative for tumor. Because of the critical
condition of the patient, therapy was begun based on cytologic findings, with expert consultation.
Six months after therapy, the patient had a pleural relapse. Pleural biopsy revealed a primitive small cell tumor
(Figure 2), with immunohistochemical positivity for kappa light chain and CD20 and negativity for desmin.
Case 4 - Figure 1 - Cytocentrifuge preparation of pleural fluid, containing a blast with round nucleus, ropy chromatin, minimal deep blue cytoplasm, and prominent cytoplasmic vacuoles.
Case 4 - Figure 2 - Pleural biopsy of initial recurrence. The tumor comprises diffuse sheets of small cells with round, hyperchromatic nuclei, minimal cytoplasm, and no obvious features of differentiation.
Case 4 - Figure 3 - Pleural biopsy of second relapse. After bone marrow transplantation, the cancer recurred and contains fibrous septa subtending nests of tumor cells with obvious rhabdomyoblastic differentiation (intensely eosinophilic cytoplasm. Prominent clefting artefact can be seen at the periphery of the nests, adjacent to alignment of the tumor cells on the edge of the fibrous septa.
Brian P. Rubin
University of Washington
1-month-old male with a 3 cm mass involving the paraspinal soft tissues of the upper back.