California Tumor Tissue Registry
Case of the Month
October, 2003
“An Elderly Woman With Bilateral
Ovarian Masses”
An 86 year old female complaining of abdominal
pain was found by abdominal CT scan to have
bilateral ovarian cysts. She underwent a TAHBSO. The ovaries approximated 21 cm in
greatest diameter and had walls that were up to
2.0 cm thick. Their inner surfaces were smooth,
without papillary structures.
Microscopically the tumor was hypercellular, and varied somewhat in cellularity (Fig. 1).
Many of the cells had clear cytoplasm, assuming a balloon-cell appearance that mimicked
lipoblasts (Fig. 2). Other regions had signet ring cells virtually indistinguishable from
those of a signet ring adenocarcinoma (Fig. 3). Mitotic figures were not encountered. A
stain for mucin was negative.
Diagnosis: “Signet-ring Stromal Tumor of Ovary”
Sajjad P Syed, MD, and Donald R Chase, MD
Department of Pathology and Human Anatomy, Loma Linda University
Medical Center, Loma Linda, California.
Signet-Ring Stromal Tumor of the Ovary (SRSTO) is an exceptionally rare neoplasm,
with only five reported cases to date. It was first described by Ramzy in 1976. So far,
none has been shown to produce any hormonally related symptoms, and it is felt that the
tumor is inert/non-functioning. They have occurred in women between the ages of 28
and 86 years.
Grossly, SRSTO is described as being either solid or cystic. Microscopically it consists
of polygonal and spindled cells which imperceptibly merge with signet-ring cells
surrounded by reticulum and/or collagen fibers. Neither pleomorphism nor
hyperchromasia has been seen, and mitotic figures are very rare. Despite their signet ring
appearance, the cells are negative for both mucin and lipid stains.
Entering into the differential diagnosis of SRSTO are Krukenberg and Sclerosing stromal
tumors:

Krukenberg Tumor is a metastatic adenocarcinoma to the ovary, often of
signet ring cells, arising in the GI tract (stomach, colon, pancreas,
gallbladder), breast or bladder. The tumor is asymmetrical, large and solid,
CTTR’s Case of the Month
October, 2003
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and usually involves both ovaries. The signet ring cells are usually mucinpositive.

Sclerosing stromal tumor is a benign, usually unilateral, ovarian stromal tumor
which occurs in young adult females and is associated with excessive estrogen
secretion. The microscopic appearance is of fibroblasts and vacuolated cells
supported by edematous hypocellular regions with variable vascularity. The
vacuolated cells, probably degenerating lutein cells, resemble signet ring cells,
and may stain positively for lipid (oil red O stain).
With only five cases of SRSTO in the literature, most of our knowledge about this tumor
is anecdotal rather than statistical. To date, none of the tumors has recurred following
complete removal, and despite the ominous presence of signet ring cells there has been
no evidence of aggressive behavior.
References and Suggested Reading:
1) Scully, Young. Clement. AFIP fascicle; Tumors of the Ovary, Maldeveloped Gonads,
Fallopian Tubes, and Broad Ligament. 3rd Series, pp 197-200.
2) Blaustein’s Pathology of the Female Genital Tract. 5th ed. Kurman RJ, pp 925-928.
3) Hainer & Taylor’s Obstetrical & Gynaecological Pathology. 4th ed, pp 842 - 843.
4) Weidner N. Differential Diagnosis in Surgical Pathology. pp 417-420.
5) Ramzy I. Signet-ring stromal tumor of the ovary: A histochemical, light, and electron
microscopic study. Cancer 38 (1):166-72, 1976.
6) Cashell AW, Jerome WG, Flores E. Signet-ring stromal tumor of the ovary occurring
in conjunction with brenner tumor. Gynecol Oncol 77(2):323-6, 2000.
7) Dickersin GR, Young RH, Scully RE. Signet-ring stromal and related tumors of the
Ovary. Ultrastruct Pathol 19(5):401-19, 1995.
8) Suarez et all. Signet-ring stromal tumor of the Ovary: A histochemical,
immunohistochemical and ultrastructural study. Virchows Arch A Pathol Anat
Histopathol. 422(4):333-6, 1993.
9) Ramzy I, Delaney M. Signet-ring stromal tumor of the ovary: Cytologic appearances
of fine needle aspiration biopsy. Acta Cytol 21(1):14-7, 1977.
10) Ramzy I. Signet-ring stromal tumor of the ovary: Histochemical, light, and electron
microscopic study. Cancer 38(1):166-72, 1976.
11) Holtz F, Hart WR. Krukenberg tumors of the ovary: A clinicopathologic analysis of
27 cases. Cancer 50(11):2438-47, 1982.
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October, 2003
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