Case 1 - Click here for Text and References
Submitted by: Jason Hornick
Clinical Summary:
A 19-year-old man presented to his primary care physician with a 6-week history of weakness and pallor. A CBC showed severe anemia. On endoscopy, multiple submucosal nodules were identified in the gastric antrum, one associated with mucosal ulceration. A biopsy was non-diagnostic. A CT scan revealed multiple large masses along the lesser curvature and gastric antrum. A distal gastrectomy was performed.
Case 1 - Slide 1
CT scan of the abdomen. There is a large, multinodular mass in the lesser curvature of the stomach.
Gross image of the gastrectomy specimen. On cross section, the wall of the stomach is replaced by multiple tumor nodules with a fleshy appearance. Several nodules are hemorrhagic.
On scanning magnification, the tumor shows a multinodular/plexiform architecture.
The individual nodules are sharply circumscribed and separated by smooth muscle of the muscularis propria.
The tumor cells show a predominantly epithelioid appearance with eosinophilic and focally clear cytoplasm.
An area of the tumor with mixed epithelioid (left) and spindle cell (right) morphology. The nuclei show mild atypia.
Immunohistochemistry for KIT is strongly positive in the tumor cells. Note the multinodular growth pattern.
Smooth muscle actin (SMA) is negative in the tumor cells. Note the infiltration through the muscularis propria.
Desmin is negative in the tumor cells.
Immunohistochemistry for SDHA shows loss of expression in the tumor cells. Note the normal cytoplasmic staining in the overlying gastric glands.
A high power image showing loss of SDHB expression in tumor cells.
A high power image showing loss of SDHA expression in tumor cells. Note the granular staining in endothelial cells.
Case 2 - Click here for Text and References
Submitted by: Carrie Y. Inwards
Clinical Summary:
59 year old male presented with a 5 month history of pain involving his right hand.
Case 3 - Click here for Text and References
Submitted by: Brian P. Rubin
Clinical Summary:
The case history is: 33 year old woman with a knee mass measuring 6.4 cm in greatest dimension.
Case 3 - Slide 1
Case 4 - Click here for Text and References
Submitted by: Judith VMG Bovee
Clinical Summary:
56 year old female. Excision of a tumor on the medial side of the right knee. Previous needle biopsy showed a myxoid tumor. No relevant medical history.
Case 5 - Click here for Text and References
Submitted by: Julia A. Bridge
Clinical Summary:
A 67-year-old man presented in 1996 with a 7 month history of increasing pain in the right foot and ankle. Following an open biopsy, a Syme amputation was performed.
A. Preoperative anteroposterior mortise and B. Broden’s view radiographs of the affected ankle showing a well-defined lytic lesion involving the body of the talus (arrow). No matrix calcification is identified. C. Coronal T1-weighted image after administration of gadolinium based contrast. Talus lesion demonstrates differential enhancement, most marked centrally with radial pattern. Several small foci of non-enhancement also present within lesion and persisted on other pulse sequences.
At low power, the relatively densely cellular lesion is arranged in a sheet-like pattern and occupies the intertrabecular bone marrow space.
Medium power demonstrates sheets of spindle-to-ovoid shaped tumor cells arranged around numerous thin-walled capillary vessels.
Focal nested/multi-lobular pattern
Focal myxoid stroma.
Closer examination demonstrates the arborizing vessels separating the tumor cells with poorly defined eosinophilic cytoplasm and ovoid vesicular nuclei that often contain a single small nucleolus.
CD34 immunostaining is negative in the tumor cells but highlights the vasculature.