Endometrioid adenocarcinoma concurrent with a blue nevus of the endometrium and uterine cervix: A case report

Abstract

A blue nevus is a benign melanocytic lesion that is composed of spindle-shaped pigmented melanocytes. Although the uterine cervix is believed to be the most common extracutaneous location of blue nevi, the occurrence of these lesions in the endometrial stroma has been reported, albeit rarely. The present study describes a case of endometrioid adenocarcinoma concurrent with a blue nevus of the endometrium and uterine cervix. A 58-year-old female presented with abnormal vaginal bleeding. A biopsy from the endometrium revealed an endometrioid adenocarcinoma and subsequently, a total hysterectomy was performed. Histopathological study revealed the proliferation of columnar cells that formed irregularly-shaped tubular and cribriform glands. The neoplastic columnar cells had large, round to oval nuclei containing a single small nucleolus. Focal squamous differentiation was noted. In the stroma of the non-neoplastic endometrium, single or small aggregates of short spindle-shaped cells containing melanin without atypia were observed. These melanocytes were also present in the endocervix. Therefore, the final diagnosis was of endometrioid adenocarcinoma concurrent with a blue nevus of the endometrium and cervix. This is the first documented case of a blue nevus of the endometrium and endocervix. The pathogenesis of blue nevi of the genital tract is not yet completely understood. Possible origins of these cells include Schwann cells or perineural cells of the peripheral nerve fiber or the abnormal migration of neural crest-derived cells.

Blue nevus presenting as an endocervical polyp

“…Concerning immunohistochemical features, the tumor cells were described as being positive for S100 protein, HMB45 and MART-1 [2,3,4,5,6,7,13]. Surprisingly, however, the immunohistochemical features described in latest edi- tion of a gynecopathology textbook were different from our findings and previous reports; that is, this textbook stated that endocervical blue nevi are usually negative for HMB45 and MART-1 [10].…”

“…Standard brown chromogen potentially induces misinterpretation of findings on melanin-loaded cells. A pre-stain bleach technique seems to provide a reasonable resolution, but may weaken immune reactivity [7]. An alternative red chromogen has a great advantage when the immunohistochemical staining targets melanin-loaded cells [17].…”

“…Blue nevi of the uterine cervix are benign melanocytic neoplasms, which were once considered to be rare and were usually found incidentally in hysterectomy specimens [1,2,3,4,5,6,7,8].…”

Primary intra‐abdominal melanoma arising in association with extracutaneous blue naevus: a report of two cases

“…1 Extremely rare extracutaneous blue naevi have been reported in lymph nodes, 2 oesophageal and rectal mucosa 3,4 and genitourinary and gynaecological tracts, most often in the prostate gland and uterine cervix. [5][6][7][8] Abnormal migration of neural crest derived melanocytes is hypothesised to underlie the pathogenesis of these unusual lesions. 9 Blue naevi in any location are variably cellular and composed of dendritic, spindled and ovoid melanocytes, usually with dense intracytoplasmic melanin pigment and a fibrotic stromal response.…”

“…Blue naevi are histologically distinct melanocytic neoplasms that arise in the dermis, rather than epidermis, and typically present as solitary, blue–grey macules, papules or plaques, and less often as nodules, on the distal extremities, scalp, trunk and buttock 1 . Extremely rare extracutaneous blue naevi have been reported in lymph nodes, 2 oesophageal and rectal mucosa 3,4 and genitourinary and gynaecological tracts, most often in the prostate gland and uterine cervix 5–8 . Abnormal migration of neural crest derived melanocytes is hypothesised to underlie the pathogenesis of these unusual lesions 9 …”