A 79-year-old black woman was recently seen by her physician for a Papanicolaou test. The test showed high-grade squamous intraepithelial lesion. The patient was asymptomatic. Follow-up endocervical curettage confirmed the lesion. At the time of diagnosis, she reported no vaginal bleeding or spotting since menopause, which began around the age of 40 years. She had never been on any hormone replacement therapy. Family history was significant for a son who died at a young age of leukemia.

Following the Papanicolaou test, a cold knife cone biopsy was performed, which revealed groups of haphazardly oriented nests of basaloid cells infiltrating the cervical stroma with overlying high-grade squamous dysplasia (Figure 1). Central squamous differentiation with microcyst formation was evident, along with nests of hyperchromatic small basaloid cells with scant cytoplasm (Figure 2). A cribriform-like arrangement of basaloid cells, resembling adenoid cystic carcinoma (ACC), was present (Figure 1, inset). Immunohistochemical staining with collagen IV outlined the collagen. No inflammation or desmoplasia accompanied the tumor nests. The relatively uniform basaloid cells did not form glands. No marked nuclear polymorphism was seen. Mitotic activity was rare. No necrosis, infiltrating cords of cells, or clear cell changes were evident.

Prior to a radical hysterectomy, speculum examination revealed a cervix flush with the posterior vaginal wall with no lesions noted. Bimanual examination also revealed a cervix flush with the posterior vaginal wall. No lesions were palpated. A small, mobile uterus with no adnexal masses was felt. Rectovaginal examination showed no parametrial involvement or rectovaginal nodularity. Gross examination of the radical hysterectomy specimen revealed no distinct mass or abnormality. The entire cervix, along with representative sections from the uterus and surgical margins, was submitted for histology. Similar tumor was present in 4 of 10 sections from the cervix. The tumor extended 4.2 mm below the epithelial surface. No lymphovascular invasion was identified, and no uterine corpus or vaginal involvement was evident.

What is your diagnosis?

Adenoid basal carcinoma (ABC) is an uncommon neoplasm of the cervix. Since the original description of this entity, fewer than 50 cases have been reported.1–3 This patient's history and presentation are typical for ABC. Patients tend to be older than those with cervical adenocarcinoma, having a median age of 65 years. Roughly half of the patients are black. They usually have no symptoms related to the disease. Cytology smears are atypical or only suspicious in most cases and are related to an overlying squamous intraepithelial lesion. Grossly, the cervix appears unremarkable or reveals a vague, mild, nodular distortion. Microscopically, ABC resembles a basosquamous cell carcinoma of the skin. The tumor is characterized by small nests and cords of uniform round or oval small cells with scant cytoplasm and hyperchromatic nuclei. Central squamous differentiation with microcystic formation is also a characteristic feature of the tumor. The squamous cells are surrounded by smaller palisaded basal cells. A few of the nests may contain small acini lined by a single layer of cuboidal or columnar cells. A desmoplastic stromal reaction or lymphocytic reaction is usually absent. Mitotic activity is rare. Depth of tumor invasion ranges from 2 to 10 mm. An associated neoplastic squamous lesion is common. Lymph node metastasis is extremely rare.

It has been shown that integrated high-risk human papillomavirus (HPV), particularly type 16, is associated with this uncommon cervical neoplasm.4 The precise mechanism underlying this unique putative carcinogenesis is unclear. However, the postmenopausal status of these patients suggests that host factors related to aging may influence tumor evolution and morphology after infection with HPV-16.5 Immunohistochemically, the basaloid cells of the ABC were positive for keratins 14, 17, and 19, a phenotype similar to reserve cells of the uterine cervix. Adenoid cystic carcinoma and ABC have similar immunohistochemical profiles, apart from type IV collagen and laminin staining, which occurred exclusively in relation to the extracellular basement membrane–like material in ACC. However, in our case, collagen IV was expressed in a small focus of ACC-like area of ABC. The similar clinical profiles, despite the different biological behavior, capacity for divergent differentiation, and the occurrence of ABC areas in some ACCs and vice versa, suggest that these tumors may share a common histogenesis, forming part of a morphologic and biologic spectrum of basaloid cervical neoplasms of putative “reserve cell” origin. Circumstantial evidence suggests that ABC may be a precursor of cervical ACC.6 In some cases of ABC, cribriform-like arrangement of basaloid cells, resembling ACC, could be present.7 

The term adenoid basal epithelioma was proposed to replace the terms adenoid basal carcinoma and adenoid basal hyperplasia, because it better describes the clinicopathologic features of these distinctive lesions and their excellent prognosis and may reduce the likelihood of unnecessarily aggressive treatment.7 

Distinction between ABC of the cervix and other diseases is important for clinical management because the clinical outcome of ABC is much more favorable. Particularly, ABC should be distinguished from squamous cell carcinoma with basaloid features and from ACC. Squamous cell carcinoma, lack of gland formation by definition, is formed by larger neoplastic cells with evidence of nuclear polymorphism, which is absent in smaller, bland-appearing cells in ABC. Squamous cell carcinoma with basaloid features is characterized by central comedonecrosis, which is not present in ABC. On the other hand, ACC is larger and usually involves the surface extensively. In addition, ACC is characterized by glandular formation with cylindromatous pattern, which is absent in ABC.

The choice of treatment for ABC is hysterectomy. Conization may not remove the usually deep-seated lesion. In the 20 cases reported in the literature to date, no metastases were noted in the typical ABC.3 

Baggish
,
M. S.
and
J. D.
Woodruff
.
Adenoid basal carcinoma of the cervix.
Obstet Gynecol
1966
.
28
:
213
218
.
Daroca
,
P. J. Jr
and
H. N.
Dhurandhar
.
Basaloid carcinoma of the uterine cervix.
Am J Surg Pathol
1980
.
4
:
235
239
.
Ferry
,
J. A.
and
R. E.
Scully
.
“Adenoid cystic” carcinoma and adenoid basal carcinoma of the uterine cervix: a study of 28 cases.
Am J Surg Pathol
1988
.
12
:
134
144
.
Grayson
,
W.
,
L. F.
Taylor
, and
K.
Cooper
.
Adenoid cystic and adenoid basal carcinoma of the uterine cervix: comparative morphologic, mucin, and immunohistochemical profile of two rare neoplasms of putative “reserve cell” origin.
Am J Surg Pathol
1999
.
23
:
448
458
.
Cviko
,
A.
,
B.
Briem
, and
S. R.
Granter
.
et al
.
Adenoid basal carcinoma of the cervix: a unique morphological evolution with cell cycle correlates.
Hum Pathol
2000
.
31
:
740
744
.
Jones
,
M. W.
,
S.
Kounelis
,
H.
Papadaki
,
A.
Bakker
,
P. A.
Swalsky
, and
S. D.
Finkelstein
.
The origin and molecular characterization of adenoid basal carcinoma of the uterine cervix.
Int J Gynecol Pathol
1977
.
16
:
301
306
.
Brainard
,
J. A.
and
W. R.
Hart
.
Adenoid basal epithelioma of uterine cervix: a reevaluation of distinctive cervical basaloid lesions currently classified as adenoid basal carcinoma and adenoid basal hyperplasia.
Am J Surg Pathol
1998
.
22
:
965
975
.

The authors have no relevant financial interest in the products or companies described in this article.

Author notes

Corresponding author: Dongfeng Tan, MD, Departments of Pathology and Cancer Genetics, Roswell Park Cancer Institute, State University of New York at Buffalo, Elm and Carlton Streets, Buffalo, NY 14263 ([email protected])