Key clinical message:
A 32-year-old breastfeeding mother with diabetes mellitus presented with
abdominal pain, weight loss, and an 8 cm pancreatic mass. Surgery
revealed a high-grade embryonal rhabdomyosarcoma. Despite R0 resection
and chemotherapy, she had early liver recurrence within three months.
Histopathology confirmed pancreatic embryonal rhabdomyosarcoma with high
Ki-67 (90%).
A 32-year-old breastfeeding mother presented with upper abdominal pain,
anorexia, vomiting, and weight loss for four months. She had been
treated with subcutaneous insulin for diabetes mellitus for the past
three years. On examination, she appeared pale and had a vague 8 cm lump
in the epigastric region. Blood tests showed low hemoglobin (7.5 gm/dl)
with normal liver and kidney function. A contrast CT scan of the abdomen
revealed a heterogeneous mass in the neck and body of the pancreas
(Figure 1), confirmed by an MRI, with no signs of metastasis. Tumor
markers were normal. After stabilizing her with blood transfusions, she
was diagnosed with a diffuse pancreatic neoplasm (solid pseudopapillary
neoplasm-SPN) and Type 3c diabetes mellitus. She underwent an extended
distal pancreatosplenectomy (Figure 2, Figure 3), as the tumor was
resectable and preoperative biopsy facilities were unavailable.
Postoperative recovery was smooth, received Pneumovac vaccination at
discharge, and histopathology was requested. On histopathological
microscopy, it revealed proliferation of atypical spindle cells arranged
in intersecting short fascicles. The IHC report confirmed high grade
sarcoma (embryonal rhabdomyosarcoma) of the pancreas (IHC image is not
available as it was done in India). Immunohistochemical staining was
positive for vimentin, desmin, myogen and MyoD1; and negative for SOX10,
MDM2, p16, CDK4, synaptophysin, CEA, ER, CK and S100. Ki-67 was 90%.
Unfortunately, despite R0 resection and adjuvant chemotherapy, she had
an early recurrence in liver at multiple sites at three months
follow-up.
Rhabdomyosarcoma (RMS) is a rare malignancy originating from embryonic
mesenchyme, with the potential to differentiate into skeletal
muscle.1 Although it accounts for about 50% of all
soft tissue sarcomas in children, it represents only 3% of such cases
in adults, usually occurring in skeletal muscle. Initially described by
Webner in 1854, RMS has since been categorized into four
histopathological types: embryonal, botryoid, alveolar, and
pleomorphic.1 RMS affecting the biliary tree is
particularly uncommon, predominantly seen in infants and children.
Shirafkan A and colleagues reported the first case of undifferentiated
pleomorphic RMS involving the pancreas, with no other similar cases
documented.2
Diagnosing RMS before surgery is challenging due to vague symptoms, such
as abdominal discomfort, weight loss, and palpable masses. Imaging often
reveals non-specific masses with peripheral enhancement, while
preoperative biopsies tend to be inconclusive since specialized staining
is rarely performed. Pathological confirmation requires identifying
atypical spindle cells arranged in intersecting fascicles, alongside
muscle-specific markers like myogen, desmin, SMA, and vimentin.
Treatment for adult RMS primarily involves surgical removal of the
tumor, followed by chemotherapy and radiotherapy. Studies indicate that
adult RMS is chemo-sensitive, with a 75% response
rate.3 The standard regimen includes vincristine,
dactinomycin, and cyclophosphamide. Prognosis is influenced by factors
like age, tumor histology, location, stage, and local control measures.
Older patients and certain histological subtypes show reduced
chemosensitivity and tolerance for aggressive
therapy.3 Patients responding to chemotherapy often
experience extended metastasis-free intervals. A study by Ogilvie
highlighted that combining chemotherapy (using doxorubicin, ifosfamide,
and vincristine) with surgery and radiation improved 2-year survival
rates to 55% overall and 64% disease-free survival.3Nonetheless, long-term outcomes for adult RMS remain poor, with survival
rates ranging from 12.5% to 50% within the first year post-treatment.
Conflict of interest: None
Funding: None
Consent: Written informed consent was obtained from the patient for
reporting this case image.
Author contribution: Both the authors contributed equally in preparing
the manuscript. Final version is approved by both authors.
Figure legends
Figure 1. Diffusely enlarged, irregular, lobulated body of pancreas with
heterogenous enhancement.
Figure 2: Intraoperative view showing mobilized pancreatic tumor with
the spleen.
Figure 3. Cut section of the specimen showing well-capsulated, fleshy
tumor.