Open Access
Open Peer Review

This article has Open Peer Review reports available.

How does Open Peer Review work?

Treatment of eccrine porocarcinoma with metastasis to the parotid gland using intensity-modulated radiation therapy: a case report

  • Youssef H Zeidan1Email author,
  • A Jason Zauls1,
  • Masha Bilic2,
  • Eric J Lentsch3 and
  • Anand K Sharma1
Journal of Medical Case Reports20104:147

DOI: 10.1186/1752-1947-4-147

Received: 28 September 2009

Accepted: 22 May 2010

Published: 22 May 2010



Cutaneous eccrine porocarcinomas are uncommon malignant tumors of the sweat gland.

Case Presentation

A 76-year-old Caucasian man presented to our hospital with a left temporal mass. We describe a case of eccrine porocarcinoma with metastasis to the parotid gland with special emphasis on the role of surgical resection and adjuvant radiation therapy.


Besides surgical resection, little is known about the role of adjuvant therapy in managing eccrine porocarcinomas. Radiation therapy should be considered within a multidisciplinary approach in patients with primary or recurrent eccrine porocarcinomas.


Eccrine porocarcinoma (EPC) is a rare malignant tumor of the sweat gland that accounts for 0.005% of all skin cancers [1]. Due to its low incidence, current knowledge about EPC is limited to case reports, with only 250 cases having been reported worldwide. Common EPC lesions occur on the lower extremities (50%) followed by the trunk (24%) or the head and neck (24%), with more than 50% of cases occurring in men [2]. EPC has also been reported to involve the vulva [3], penis [4] and upper extremities [5]. Although the age at presentation ranges from 19 to 90 years [6], EPC tends to affect the elderly, at an average age of 68. Surgical resection remains the gold standard for treatment. There is a 17% incidence of local recurrence and an 11% incidence of distant metastasis [7], which indicates that there is a role for adjuvant therapy.

We report the case of a patient with cutaneous EPC with secondary metastasis to the parotid gland who was treated with intensity-modulated radiation therapy after surgical resection.

Case Presentation

A 76-year-old Caucasian man presented with a long history of a left temporal lesion that had progressively enlarged only recently. Initial surgical excision yielded a mass measuring 2.5 × 2.2 × 1 cm. Histological examination revealed tumor islands infiltrating the dermis and connecting to the epidermis with a lobulated morphology (Figure 1). Since the deep resection margin was positive for malignant cells, a re-excision was performed and negative margins were verified microscopically. Eight months later, our patient presented with a 2 cm firm mass overlying the left parotid gland with minimal mobility on physical examination (Figure 2). Whole body imaging in the form of a positron emission tomography (PET) scan showed increased uptake in the left parotid gland, which was consistent with metastasis. Our patient underwent left parotidectomy with facial nerve preservation and cervical lymphadenectomy. Surgical pathology specimens revealed a moderately differentiated carcinoma with growth pattern and morphological features consistent with porocarcinoma. Microscopically, nests of polygonal malignant cells were seen infiltrating the papillary and reticular dermis (Figure 3). A surrounding dense fibrous stroma could be visualized (Figure 3). The cervical lymph nodes (14 in total) were negative.
Figure 1

Photomicrograph of the initial left temporal mass showing islands of polygonal tumor cells invading the dermis (hematoxylin and eosin, 10×).
Figure 2

Macroscopic view showing a new left parotid lesion and a scar at the previous frontotemporal lesion.
Figure 3

Photomicrographs of surgical pathology specimens. (A-B) Photomicrograph of left parotid mass showing tumor cells of similar cytology to the original temporal mass infiltrating the parotid gland. Ductal structures characteristic of eccrine porocarcinoma are seen (hematoxylin and eosin, 4× to 20×).

Given the aggressive behavior of EPC described in the literature and evidence for the effective use of radiation therapy [8], our patient was offered intensity-modulated radiation therapy (IMRT). After initial consultation at the Head and Neck Radiation Oncology Clinic of the Medical University of South Carolina (MUSC) Hollings Cancer Center, a consent form was obtained. Treatment planning consisted of a contrasted head and computed tomography (CT) scan of the neck with our patient lying supine, using a head and neck thermoplast mask with bite block immobilization. Thin (3 mm) axial images were imported into the ADAC Pinnacle planning system (ADAC Laboratories, Milpitas, CA, USA). In this case, IMRT was designed using an inverse-planning algorithm.

The six-beam heterogeneous plan entailed delivering a total of 60 Gy in 30 treatment fractions over six weeks. A CT scan with isodose distributions and a dose-volume histogram for the final treatment plan are shown in Figure 4. Particular attention was directed to regions of interest such as the left inner ear and optic nerve, to minimize radiation exposure well below the reported tolerance doses of 40 Gy and 50 Gy, respectively [9].
Figure 4

(A) Axial, saggital and coronal CT images showing the final intensity-modulated radiation therapy (IMRT) plan and isodose distributions around the tumor bed. Gross tumor volume (GTV) is outlined from contrast enhanced planning CT scan. Isodose lines of decreasing energies radiate out from the center of the tumor bed. The tumor is completely contained by the 95% isodose blue line (57 Gy). (B) Cumulative dose-volume histogram (DVH) of the IMRT plan. The curves illustrate the dose distribution for the clinical target volume (CTV: defined as GTV +0.5 cm), mandible, left parotid, optic nerves, optic chiasm and a cervical lymph node.

Weekly on-site treatment visits were documented during the treatment phase of our patient, followed by scheduled three-month follow-up visits. Our patient tolerated the radiation treatment well, and developed only mild xerostomia and mild paresthesias. Further follow-up revealed that our patient remains disease-free 10 months after completion of the treatment course.


Eccrine porocarcinoma is challenging to diagnose based on clinical presentation alone, and histopathological examination is almost always required. Typically, a patient presents with an erythematous papule with a recent change in size, bleeding or itching. The differential diagnosis includes squamous cell carcinoma (SCC), basal cell carcinoma, Paget's disease and metastatic cancer. Positive staining for periodic acid-Schiff (PAS), carcinoembryonic antigen (CEA) or angiotensin type 1 receptor can aid in making the diagnosis [10, 11]. Although the etiology remains unknown, it has been suggested that EPC arises from the malignant transformation of eccrine poroma. Interestingly, an association has been proposed between EPC and the immuncompromised states such as human immunodeficiency virus (HIV), diabetes and organ transplantation [12].

Wide local excision [7] and Mohs surgery [13] are widely accepted treatment modalities for primary EPC. Surgical excision has a cure rate of 70-80% and a local recurrence rate of 20%. Excellent outcomes have been reported following Moh's surgery, with patients in remission after five years of follow-up.

Based on the literature, the role of chemotherapy in the treatment of EPC remains unclear. Orphan cases with good responses to 5-fluorouracil [14], thiotepa and Cytoxan (cyclophosphamide) [15] have been reported. However, other studies have described cases showing no clinical response to chemotherapy [16]. In one report, four cases of pediatric EPC were treated with a combination of 5-fluorouracil, doxorubicin and cyclophosphamide. No response was observed after one year of therapy [17]. In general, chemotherapy, if considered at all, is reserved for metastatic EPC.

On the other hand, the role of radiation therapy in EPC seems to have changed over the years from radioresistance in earlier reports [15] to good local control in more recent studies [16]. Perhaps the changes in these anecdotal reports reflect the evolution of technological advances in radiation therapy over time. Combinations of photons and electrons were used in several cases. Table 1 summarizes reported cases and outcomes of EPC involving radiation therapy.
Table 1

Summary of reported eccrine porocarcinoma cases involving adjuvant radiation therapy.







70 Gy to tumor and 50 Gy to regional LNs

24 months



71.6 Gy to tumor and 50 Gy to supraclavicular LNs

35 months



70 Gy to parotid and 46 Gy to lower cervical LNs

27 months


Scalp and cervical LNs

76.4 Gy to scalp and 76.5 Gy to posterior cervical LNs

Death at 6 weeks


Inguinal and para-aortic LNs

50.4 Gy

8 months


Left vulva

50.4 Gy to left pelvis and 60 Gy to left inguinal LNs

19 months


LNs: lymph nodes; XRT: radiation therapy.

Until further studies on EPC are conducted, one can extrapolate important lessons from clinical experience with the more common SCC of the head and neck. The parotid gland is a common site for metastasis of cutaneous tumors of the scalp, frontotemporal and periauricular regions. Poor outcomes have been associated with parotid disease, with a two-year survival of only 74%. Survival of patients drops further to 67% when parotid disease is concurrent with neck disease [18]. Patients who require parotidectomy are more likely to have recurrent lesions. Given the importance of parotid involvement, some authorities have advocated modifying the current American Joint Commission on Cancer (AJCC) staging for metastatic cutaneous carcinoma in order to distinguish parotid from neck diseases [19]. Post-operative radiation therapy has emerged as an integral part of the care for aggressive cutaneous carcinoma patients with parotid invasion. A landmark study by Taylor et al. demonstrated that patients treated with post-operative radiation therapy had 89% local disease control, compared to 63% for those treated with surgery alone and 46% for those treated with radiation alone [8]. In a more recent study, Weber and colleagues further confirmed the value of a dual approach of surgery and radiation therapy [20].


More than 45 years after its original description by Pinkus and Mehregan [21], guidelines for staging and treatment EPC are still lacking. The current report describes the presentation and management of an interesting case of cutaneous EPC with metastasis to the parotid gland. Although the short follow-up period is a limitation, to the best of our knowledge there has only been one previously reported case akin to ours [22]. Because of its aggressive potential for metastatic spread, a multidisciplinary approach involving surgery, pathology and radiation therapy should be considered in the management of EPC.


Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.



American Joint Commission on Cancer


carcinoembryonic antigen


computed tomography


eccrine porocarcinoma


human immunodeficiency virus


intensity-modulated radiation therapy


periodic acid-Schiff


positron emission tomography


squamous cell carcinoma.


Authors’ Affiliations

Department of Radiation Oncology, Medical University of South Carolina
Department of Pathology, Medical University of South Carolina
Department of Otolaryngology, Medical University of South Carolina


  1. Cowden A, Dans M, Militello G, Junkins-Hopkins J, Van Voorhees AS: Eccrine porocarcinoma arising in two African American patients: distinct presentations both treated with Mohs micrographic surgery. Int J Dermatol. 2006, 45 (2): 146-150. 10.1111/j.1365-4632.2006.02735.x.View ArticlePubMedGoogle Scholar
  2. Sosnowski J, Stetter-Neel C, Cole D, Durham JP, Mawhinney MG: Protein kinase C mediated anti-proliferative glucocorticoid-sphinganine synergism in cultured Pollard III prostate tumor cells. J Urol. 1997, 158 (1): 269-274. 10.1097/00005392-199707000-00084.View ArticlePubMedGoogle Scholar
  3. Katsanis WA, Doering DL, Bosscher JR, O'Connor DM: Vulvar eccrine porocarcinoma. Gynecol Oncol. 1996, 62 (3): 396-399. 10.1006/gyno.1996.0255.View ArticlePubMedGoogle Scholar
  4. Grayson W, Loubser JS: Eccrine porocarcinoma of the penis. J Urol. 2003, 169 (2): 611-612. 10.1016/S0022-5347(05)63966-3.View ArticlePubMedGoogle Scholar
  5. Mehregan AH, Hashimoto K, Rahbari H: Eccrine adenocarcinoma. A clinicopathologic study of 35 cases. Arch Dermatol. 1983, 119 (2): 104-114. 10.1001/archderm.119.2.104.View ArticlePubMedGoogle Scholar
  6. Goedde TA, Bumpers H, Fiscella J, Rao U, Karakousis CP: Eccrine porocarcinoma. J Surg Oncol. 1994, 55 (4): 261-264. 10.1002/jso.2930550413.View ArticlePubMedGoogle Scholar
  7. Robson A, Greene J, Ansari N, Kim B, Seed PT, McKee PH, Calonje E: Eccrine porocarcinoma (malignant eccrine poroma): a clinicopathologic study of 69 cases. Am J Surg Pathol. 2001, 25 (6): 710-720. 10.1097/00000478-200106000-00002.View ArticlePubMedGoogle Scholar
  8. Taylor BW, Brant TA, Mendenhall NP, Mendenhall WM, Cassisi NJ, Stringer SP, Million RR: Carcinoma of the skin metastatic to parotid area lymph nodes. Head Neck. 1991, 13 (5): 427-433. 10.1002/hed.2880130510.View ArticlePubMedGoogle Scholar
  9. Emami B, Lyman J, Brown A, Coia L, Goitein M, Munzenrider JE, Shank B, Solin LJ, Wesson M: Tolerance of normal tissue to therapeutic irradiation. Int J Radiat Oncol Biol Phys. 1991, 21 (1): 109-122.View ArticlePubMedGoogle Scholar
  10. Hara K, Kamiya S: Pigmented eccrine porocarcinoma: a mimic of malignant melanoma. Histopathology. 1995, 27 (1): 86-88. 10.1111/j.1365-2559.1995.tb00298.x.View ArticlePubMedGoogle Scholar
  11. Arslan E, Tatar C, Aksoy A, Tutuncu N: De novo malignant eccrine poroma of the nose: a review of the midface as a location. Plast Reconstr Surg. 2004, 113 (7): 2227-2229.View ArticlePubMedGoogle Scholar
  12. Mahomed F, Blok J, Grayson W: The squamous variant of eccrine porocarcinoma: a clinicopathological study of 21 cases. J Clin Pathol. 2008, 61 (3): 361-365. 10.1136/jcp.2007.049213.View ArticlePubMedGoogle Scholar
  13. Wittenberg GP, Robertson DB, Solomon AR, Washington CV: Eccrine porocarcinoma treated with Mohs micrographic surgery: A report of five cases. Dermatol Surg. 1999, 25 (11): 911-913. 10.1046/j.1524-4725.1999.99121.x.View ArticlePubMedGoogle Scholar
  14. Swanson JD, Pazdur R, Sykes E: Metastatic sweat gland carcinoma: response to 5-fluorouracil infusion. J Surg Oncol. 1989, 42 (1): 69-72. 10.1002/jso.2930420114.View ArticlePubMedGoogle Scholar
  15. el-Domeiri AA, Brasfield RD, Huvos AG, Strong EW: Sweat gland carcinoma: a clinico-pathologic study of 83 patients. Ann Surg. 1971, 173 (2): 270-274. 10.1097/00000658-197102000-00014.View ArticlePubMedPubMed CentralGoogle Scholar
  16. Shiohara J, Koga H, Uhara H, Takata M, Saida T: Eccrine porocarcinoma: clinical and pathological studies of 12 cases. J Dermatol. 2007, 34 (8): 516-522. 10.1111/j.1346-8138.2007.00324.x.View ArticlePubMedGoogle Scholar
  17. Chow CW, Campbell PE, Burry AF: Sweat gland carcinomas in children. Cancer. 1984, 53 (5): 1222-1227. 10.1002/1097-0142(19840301)53:5<1222::AID-CNCR2820530533>3.0.CO;2-A.View ArticlePubMedGoogle Scholar
  18. Khurana VG, Mentis DH, O'Brien CJ, Hurst TL, Stevens GN, Packham NA: Parotid and neck metastases from cutaneous squamous cell carcinoma of the head and neck. Am J Surg. 1995, 170 (5): 446-450. 10.1016/S0002-9610(99)80326-2.View ArticlePubMedGoogle Scholar
  19. O'Brien CJ, McNeil EB, McMahon JD, Pathak I, Lauer CS, Jackson MA: Significance of clinical stage, extent of surgery, and pathologic findings in metastatic cutaneous squamous carcinoma of the parotid gland. Head Neck. 2002, 24 (5): 417-422. 10.1002/hed.10063.View ArticlePubMedGoogle Scholar
  20. Lai SY, Weinstein GS, Chalian AA, Rosenthal DI, Weber RS: Parotidectomy in the treatment of aggressive cutaneous malignancies. Arch Otolaryngol Head Neck Surg. 2002, 128 (5): 521-526.View ArticlePubMedGoogle Scholar
  21. Pinkus H, Mehregan AH: Epidermotropic eccrine carcinoma. A case combining features of eccrine poroma and Paget's dermatosis. Arch Dermatol. 1963, 88: 597-606.View ArticlePubMedGoogle Scholar
  22. Harari PM, Shimm DS, Bangert JL, Cassady JR: The role of radiotherapy in the treatment of malignant sweat gland neoplasms. Cancer. 1990, 65 (8): 1737-1740. 10.1002/1097-0142(19900415)65:8<1737::AID-CNCR2820650813>3.0.CO;2-Q.View ArticlePubMedGoogle Scholar
  23. DaSilva MF, Terek R, Weiss AP: Malignant eccrine poroma of the hand: a case report. J Hand Surg Am. 1997, 22 (3): 511-514. 10.1016/S0363-5023(97)80022-6.View ArticlePubMedGoogle Scholar
  24. Yamashita H, Kadono T, Tamaki K, Nakagawa K: Interesting response to concurrent chemoradiation in metastatic eccrine porocarcinoma. J Dermatol. 2008, 35 (9): 606-607. 10.1111/j.1346-8138.2008.00533.x.View ArticlePubMedGoogle Scholar


© Zeidan et al; licensee BioMed Central Ltd. 2010

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.