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May 2019
A 51-YEAR-OLD FEMALE WITH A SUBCUTANEOUS NODULE
Contributors:
Rumeal D. Whaley, MD
PGY-3 Resident Physician, Anatomic Pathology and Clinical Pathology
Indiana University School of Medicine
Shengjie Cui, MD, PhD
Department of Ophthalmology, Visual and Anatomical Sciences
Wayne State University School of Medicine
Jingmei Lin, MD, PhD
Associate Professor
Department of Pathology & Laboratory Medicine
Indiana University School of Medicine
Clinical history: The patient is a 51-year-old female G5, P4-0-0-4 at 39 plus 2 weeks who presented for scheduled repeat cesarean delivery. Her pregnancy was complicated by four prior cesarean deliveries and advanced maternal age. During the operation, extensive adhesive disease was encountered and a firm subcutaneous mass at near the prior incision site. The mass was removed and sent to surgical pathology. She delivered a heathy female infant and had an overall uncomplicated postpartum course.
Gross examination: The specimen consisted of an ellipse of tan-brown skin that measured 15.0 x 2.0 cm and was excised to a depth of 2.5 cm. A well-circumscribe adherent nodule was apparent at one tip that was 4.5 x 3.5 x 2.3 cm. The cut surface of the nodule was tan-white, whorled, and homogeneous.
Microscopic examination and immunohistochemistry: Histologic examination of the nodule revealed a proliferation of epithelioid cells clustered together in nests separated by fibrous tissue [Image 1]. The epithelioid cells had abundant grayish cytoplasm and large vesicular nuclei with prominent nucleoli [Image 2]. Within the cellular nests were rare glands. The majority of the glands were compressed by the epithelioid cells. The glands where the lumina were evident were lined by cuboidal cells [Image 2]. These cells displayed eosinophilic cytoplasm and small uniform nuclei. There was no appreciable mitotic activity throughout the lesion. The fibrous septae consisted of bland spindle cells, a sprinkling of chronic inflammatory cells, and few blood vessels. Cytokeratin AE1/AE3 highlighted the glandular epithelium while sparing the epithelioid cells [Image 3]. PAX-8 showed strong diffuse staining of the glandular epithelium and patchy weak staining of the epithelioid cells [Image 4].
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Fig. 1 . Low power view of nests of epithelioid cells
Fig.1
Fig 2: High power view of epithelioid cells and glands
Fig 2: High power view of epithelioid cells and glands
Fig. 3: Cytokeratin AE1/3 immunohistochemical stain
Fig. 3:
Fig 4: PAX-8 immunohistochemical stain
Fig.4
May 2019 Final Diagnosis and Discussion