15018752330
发表时间:2015-11-26 浏览次数:498次
Introduction
Cancer of unknown primary site (CUPS) is a clinical syndrome that is considered in patients where, even after extensive standard clinical, pathological and radiological evaluation, the primary site cannot be identified. Patients with CUPS account for 0.5-4% of all cancers diagnosed. Within this heterogeneous group, there is a wide variation of clinical presentations and histological types. Most present as a metastatic disease, which is often difficult to categorize using histology alone. Immunohistochemistry (IHC) is helpful in separating carcinomas from a neoplasm of other lineages. CUPS is more common in the head and neck and axillary regions, and inguinal involvement accounts for < 5% of cases. Metastatic inguinal lymphadenopathy mainly originates from the genitalia and anorectal areas. In this case report, we describe an uncommon case of two different histological types of metastases in inguinal nodes with unknown primary sites.
Case Report
A 49-year-old male patient, a farmer, presented in October 2012 to the surgical oncology clinic with swelling in the right groin crease for 2 years, which had been increasing progressively in size and subsequently became ulcerated. On examination the mass was hard, irregular in shape due to the conglomeration of inguinal lymph nodes, about 5 cm in diameter, fixed to the skin and deeper structures, and superficially ulcerated [Figure 1]. Bilateral hydroceles were also present. No other enlarged lymph nodes in other regions were palpable. Per rectal examination and clinical evaluation, the genitals were normal. Fine-needle aspiration cytology of the node was suggestive of squamous cell carcinoma. For better categorization, a biopsy was performed, which was suggestive of poorly differentiated squamous cell carcinoma. On contrast-enhanced computed tomography (CT) scan, an ill-defined mass lesion of 5 cm × 4 cm was noted over right inguinal region encasing the femoral vein and having 180° contact with the femoral artery [Figure 2]. Right external iliac and obturator nodes were also enlarged. The remainder of the abdomen and chest were normal. Positron emission tomography (PET) scan showed increased tracer uptake in right inguinal, external iliac, and obturator nodes, but a primary site could not be visualized. Ultrasound evaluation of the testes was normal. Upper and lower gastrointestinal endoscopy were normal. Serum carcinoembryonic antigen, CA19-9, alpha-fetoprotein, prostate specific antigen, and beta human chorionic gonadotropin were within normal range.
Discussion
The inguinal area is a relatively uncommon metastatic site of CUPS. There has
been a wide variety of primary sites from where inguinal nodal metastasis has
been reported. These include some sites, which are quite distant from the pelvis
(nasopharynx, breast, tracheobronchial tree, salivary glands, orbit) but most
originate in the pelvis, genitalia or lower limb. In one of the largest series,
involving more than 2,000 patients with inguinal nodal metastasis, the primary
site could not be identified in 22 (1%), even after a significant period of
follow-up. In the present case, even after extensive attempts to find the
primary site, the site could not be determined. The final histopathology of this
patient showed a mixed picture of squamous and transitional cell carcinoma, with
the former predominating. A literature search revealed no such report of two
different histological types of tumors, squamous and transitional, in the same
patient at the same site, from an unknown primary site, although there are
reports of mixed squamous and adenocarcinomas.
The clinical investigative
approach toward CUPS patients is mainly directed according to the
histopathology, and every attempt should be made to obtain a good tissue sample
for detailed IHC analysis. Investigations should involve a multi-modality
approach. The role of PET scan is yet to be established but has the potential to
modify the treatment in some patients whose tumor was localized with CT. As
early as 1979, it was emphasized that the analysis of tissue samples should help
to eliminate the need for undirected investigations screening for the primary
site. Since then, there have been significant advances in the molecular
analysis of tumors, and so the incidence of CUPS has decreased.
Since
CUPS in the inguinal region is rare, there is a paucity of literature on the
management of such patients, and no clear guidelines are described. The mainstay
of treatment is surgery, with complete surgical excision through systematic
lymph nodal dissection being mandatory. Aggressive surgical treatment including
vascular resection and reconstruction with grafting may be required to achieve
tumor-free margins, as was the situation in this case. Although role of
postoperative radiotherapy is not clearly defined, it is thought that, in the
presence of extensive nodal involvement and/or extranodal spread of tumor,
postoperative radiotherapy should be used as it would be with any known primary
site with squamous cell carcinoma. A review article indicates that surgery with
adjuvant irradiation was the preferred treatment for inguinal metastasis with
the unknown primary site.
A diligent follow-up is required for these
patients. In one case report described an occult carcinoma of the penis
manifested 3 years after treatment of inguinal nodal metastasis. According to
the authors, circumcision and random biopsy of glans should be a routine of such
patients. The patient in the present case was also followed up clinically,
radiologically, and with cystoscopy in view of the presence of transitional cell
carcinoma.
Carcinoma of unknown primary with inguinal metastasis is a
rare entity. Investigations should be directed to identify the primary site
according to histopathology. Although there are no clear guidelines for the
management of such patients, treatment should be multimodal, including
aggressive surgical resection, and postoperative radiotherapy. The possible role
of chemotherapy is unknown. A diligent follow-up is a must. In the future,
molecular studies may increase our ability to distinguish subtypes of CUSP and
treat them differentially.
References
1.Greco FA, Hainsworth JD. Introduction: Unknown primary cancer. Semin Oncol 2009;36:6-7.
2.Zaren HA, Copeland EM 3rd. Inguinal node metastases. Cancer 1978;41:919-23.
3.Guarischi A, Keane TJ, Elhakim T. Metastatic inguinal nodes from an unknown primary neoplasm. A review of 56 cases. Cancer 1987;59:572-7.
4.Pavlidis N, Pentheroudakis G. Cancer of unknown primary site. Lancet 2012;379:1428-35.
5.Wallack MK, Reynolds B. Cancer to the inguinal nodes from an unknown primary site. J Surg Oncol 1981;17:39-43.
6.Massard C, Loriot Y, Fizazi K. Carcinomas of an unknown primary origin - diagnosis and treatment. Nat Rev Clin Oncol 2011;8:701-10.
7.Takeuchi T, Yasui T, Izeki M, Komune S. Adenosquamous carcinoma of unknown primary origin: a case report and literature review. J Laryngol Otol 2015;129 Suppl 2:S91-4.
8.Alberini JL, Belhocine T, Hustinx R, Daenen F, Rigo P. Whole-body positron emission tomography using fluorodeoxyglucose in patients with metastases of unknown primary tumours (CUP syndrome). Nucl Med Commun 2003;24:1081-6.
9.Osteen RT, Kopf G, Wilson RE. In pursuit of the unknown primary. Am J Surg 1978;135:494-7.
10.Oien KA, Dennis JL. Diagnostic work-up of carcinoma of unknown primary: from immunohistochemistry to molecular profiling. Ann Oncol 2012;23 Suppl 10:x271-7.
11.Pavlidis N, Briasoulis E, Hainsworth J, Greco FA. Diagnostic and therapeutic management of cancer of an unknown primary. Eur J Cancer 2003;39:1990-2005.
12.Sinha M, Katema M, Malata CM. Squamous cell carcinoma of penis presenting as groin metastasis 3 years before the primary. J Plast Reconstr Aesthet Surg 2006;59:547-9.