Primary Squamous
Cell Carcinoma of the Parotid Gland Batsakis, MD; Kenneth D. McClatchey, DDS, MD; Michael Johns, MD; Joseph Regazi, DDS
John G.
\s=b\ Primary squamous cell carcinoma of the parotid gland occurs infrequently. A retrospective study at the University of Michigan indicates an incidence of 0.3% for all parotid tumors during a 25-year period. This conforms to the data presented by other large series. Before a diagnosis of primary squamous cell carcinoma can be made, mucoepidermoid carcinomas and metastatic squamous cell carcinomas must be excluded.
(Arch Otolaryngol 102:355-357, 1976)
neoplasm in our surgical and patho¬ logic material, a retrospective study of primary squamous cell carcinomas of the parotid gland observed at the Department of Otorhinolaryngology of the University of Michigan Hospi¬ tal
was undertaken. This report presents the results of that study.
SUBJECTS AND METHODS
Surgical and pathologic records from 580 patients (1950 to 1975) with parotid tumors
examined. Fourteen of the tumors were originally classified as "primary squamous cell carcinomas" of the parotid gland. The clinical records and prepared histopathologic sections of these 14 pa¬ tients were reviewed, and the neoplasms were reclassified. In addition, histochemical studies (PAS-Alcian blue at pH 2.5) were performed to identify mucin in selected cases, and, in one instance, the neoplasm was studied by electron micros¬ were
The frequency
with which a pri¬ mary squamous cell carcinoma occurs in the parotid gland is not easy to ascertain by reviewing reports in the literature. Data are presented that indicate the incidence ranges from 0% to 3.4% of all parotid tumors.1 Piqued by this diversity and also because we have been impressed by the apparently low incidence of this -
Accepted
for publication Feb 2, 1976. From the departments of pathology (Drs Batsakis, McClatchey, and Regazi) and otorhinolaryngology (Dr Johns), University of Michigan Medical School, Ann Arbor, Mich. Reprint requests to Department of Pathology, University of Michigan Medical School, 1335 E Catherine St, Ann Arbor, MI 48104 (Dr Batsa-
kis).
copy.
After review,
only
two
neoplasms qual¬
ified as primary squamous carcinomas of the parotid gland. Five of the so-called primary squamous cell carcinomas were mucoepidermoid carcinomas, and seven were metastatic carcinomas that origi¬ nated in the oral cavity, oropharynx, or skin of the lateral part of the face. The case histories of the two patients with primary squamous cell carcinomas are briefly described.
REPORT OF CASES Clinical Findings
61-year-old man who had a at the angle of the right mandible of three years' duration was seen at the University of Michigan Hospital. A tender, painful, hard, and fixed Case 1.—A
painful
mass
6.0 x 4.0
x
3.0-cm
mass was
found in the
superficial lobe of the right parotid gland. There were no palpable lymph nodes. Results of oral, nasopharyngeal, and indi¬
laryngoscopic examinations were neg¬ ative. Although the mass was fixed to the overlying skin, there were no demonstrable lesions of the skin of the head and neck. Chest roentgenograms gave negative find¬ ings. The patient underwent a total paroti¬ dectomy with an interposition graft of the greater auricular nerve and a radical dissection of the right side of the neck. Two lymph nodes from the supraomohyoid portion of the neck dissection contained metastatic squamous cell carcinoma. At the time of a 21-year follow-up, the patient had no evidence of recurrence or métastases. rect
Case 2.—A 74-year-old woman entered the University of Michigan Hospital com¬ plaining of a swelling at the angle of the left mandible that had been present for the preceding six weeks. A 3.0 3.0 x 3.0-cm, firm, fixed, nontender mass was demon¬ strated in the superficial lobe of the parotid gland. There was a slight weakness of the orbicularis oris muscle. The left jugulodigastric lymph node was hard, yet
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movable. Complete examination of the upper aerodigestive tract did not reveal a neoplasm. Chest x-ray films were normal. The patient underwent a total parotidec¬
tomy and sacrifice of the facial nerve (except for the frontal branch). The
seventh nerve was grafted with a section from the great auricular nerve. A radical dissection of the left side of the neck, including the sternocleidomastoid muscle was also performed. Only one (jugulodi¬ gastric) lymph node of 20 removed contained metastatic, well-differentiated squamous cell carcinoma.
Pathologic Findings The gross and microscopical appearance of both neoplasms were nearly identical. Both neoplasms were grayish-white, with variable degrees of cavitation, most severe in case 1. The superficial lobe was completely replaced in the neoplasm from the patient in case 1. Two thirds of the superficial lobe was replaced by the
neoplasm in case 2. Histologically, both neoplasms were moderately well differentiated, keratinizing squamous cell carcinomas (Fig 1). Both infiltrated the adjacent salivary gland parenchyma peripherally from a central cystic area. Although the latter could be interpreted as a dilated neoplastic duct, this would be entirely speculative and there was no direct proof. In neither gland was there microscopical evidence of un¬ derlying sialadenitis or ductal squamous metaplasia. Electron microscopy was performed on the buffered, formalin-fixed neoplasm from case 2, and this is shown in Fig 2.
Fig 1 .—Infiltrating margin of keratinizing squamous cell carcinoma in case 1. Histopath¬ ological appearance of primary squamous cell carcinoma in case 2 was nearly identical (hematoxylin-eosin 400).
COMMENT
Our study indicates that primary squamous cell carcinoma of the parot¬ id gland is a rare neoplasm at the
University of Michigan Hospital. The incidence of 0.3% of all parotid tumors during a 25-year period compares nearly exactly with that reported by Eneroth' after
review of 2,158 earlier publica¬ parotid tion, Eneroth' cited an incidence of 0.1% and included primary squamous cell carcinoma of the parotid in a "miscellaneous" category along with primary melanoma and malignant supporting tissue neoplasms of that gland. Woods et al,"' after studying 1,360 primary tumors of the parotid gland, gave an incidence of 1.5% for primary squamous cell carcinomas. These neoplasms made up nearly 10% a
tumors. In
an
Fig 2.—Electron microscopic appearance of squamous cell carcinoma in case 2. Epithelial cells contain abundant tonofilaments that are in bundles in some cells. Cells are connected by well-developed desmosomes (original magnification 7,500).
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of their primary malignant tumors of the parotid gland. In the study of Spiro et al,6 there were ten cases of primary squamous cell carcinoma of the parotid gland in a total of 1,875 parotid tumors (0.5%). These made up 3% of all primary malignant neo¬ plasms of the parotid gland. The foregoing statistics contrast with the 3.4% incidence given by Foote and Frazell- in 1953 (Table) and very likely reflect a refinement in histopathologic diagnosis and classifi¬ cation since their paper. Before ascribing a primary origin of a squa¬ mous cell carcinoma in the parotid gland, one must exclude mucoepidermoid carcinoma and extension or metastasis to the parotid gland from an extraparotid source. Foote and Frazell- were cognizant of this, often requiring accessory data before deem¬ ing the lesion as primary in the sali¬ vary gland. With regard to mucoepidermoid carcinomas, this quotation from their paper is pertinent: "We have on a number of occasions clas¬ sified certain salivary gland tumors as squamous and then later changed this classification to mucoepidermoid af¬ ter more material from the primary,
Cell Carcinomas of the Parotid Gland
Primary Squamous
No. of Pri-
Series
University of Michigan
Eneroth« EnerotW Woods et ais Spiro et al« Foote and Frazell*
No. of Parotid Tumors 580 802
2,158
mary
Squa-
Cell Carcinomas mous
(0.3%) (0.1%) 7(0.3%) (1.5%) 2 1
1,360 1,875
10(0.5%)
766
26(3.4%)
or metastatic tumors be¬ available for study."- Such was the situation in five of our cases, where additional tissue and/or mucin stains appropriately classified the lesion in question.
recurrent, came
If, additionally, métastases or con¬ tiguous involvement are excluded, the frequency of primary squamous cell carcinoma is probably nearer to 1% or less of all parotid gland tumors.7 This figure is very near the 1.5% incidence given for métastases to the parotid gland from squamous cell skin cancer of the head and neck.s The anatomic site of origin for primary squamous cell carcinomas of
the parotid gland has not been traced, but as Foote and FrazelP have pointed out, it is only rational to ascribe them to duct origin. As in our two cases, the local infiltration by the neoplasm ob¬ literates an identifiable point of
origin.
To our knowledge, all, or nearly all, of the reported primary squamous cell carcinomas of the parotid gland have been well or moderately well differen¬ tiated carcinomas.-" There is no mucus production, and intracellular keratinization, intercellular bridging, and keratin pearl formation are often noted. In short, there is nothing to histologically distinguish these squa¬ mous cell carcinomas from those arising in other sites. Local recurrence and regional lymph node métastases are the usual outcome for patients with primary squamous cell carcinomas of the pa¬ rotid gland.2 Spiro et al" report that seven of their ten patients eventually manifested lymph node métastases. Ultimate survival appears to depend more on the clinical stage of the disease than on the histologie ap¬ pearance of the tumor. Distant metastases are not a prominent feature. "
References 1. Bruzelius S, Cederquist E, Tinell F, et al: Tumors of the parotid gland: A histologic study and results of combined surgical and radiological treatment. Acta Chir Scand 114:1-9, 1957. 2. Foote FW Jr, Frazell EL: Tumors of the major salivary glands. Cancer 6:1065-1133, 1953. 3. Eneroth C-M: Salivary gland tumors in the parotid gland, submandibular gland, and the palate region. Cancer 27:1415-1418, 1971.
4. Eneroth C-M: Histopathological and clinical aspects of parotid tumours. Acta Otolaryngol Suppl 191:1-99, 1964. 5. Woods
ence
JE, Chong GC, Beahrs OH: Experiprimary parotid tumors. Am J
with 1,360
Surg 130:460-462, 1975. 6. Spiro RH, Huvos AG, Strong EW: Cancer of the parotid gland: A clinicopathologic study of 288 primary cases. Am J Surg 130:452-459,
1975. 7. Batsakis JG: Tumors of the Head and Neck: Clinical and Pathological Considerations. Baltimore, Williams & Wilkins Co, 1974, p 25. 8. Ridenhour CE, Spratt JS Jr: Epidermoid carcinoma of the skin involving the parotid gland. Am J Surg 112:504-507, 1966.
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Cell Carcinoma of the Parotid Gland Batsakis, MD; Kenneth D. McClatchey, DDS, MD; Michael Johns, MD; Joseph Regazi, DDS
John G.
\s=b\ Primary squamous cell carcinoma of the parotid gland occurs infrequently. A retrospective study at the University of Michigan indicates an incidence of 0.3% for all parotid tumors during a 25-year period. This conforms to the data presented by other large series. Before a diagnosis of primary squamous cell carcinoma can be made, mucoepidermoid carcinomas and metastatic squamous cell carcinomas must be excluded.
(Arch Otolaryngol 102:355-357, 1976)
neoplasm in our surgical and patho¬ logic material, a retrospective study of primary squamous cell carcinomas of the parotid gland observed at the Department of Otorhinolaryngology of the University of Michigan Hospi¬ tal
was undertaken. This report presents the results of that study.
SUBJECTS AND METHODS
Surgical and pathologic records from 580 patients (1950 to 1975) with parotid tumors
examined. Fourteen of the tumors were originally classified as "primary squamous cell carcinomas" of the parotid gland. The clinical records and prepared histopathologic sections of these 14 pa¬ tients were reviewed, and the neoplasms were reclassified. In addition, histochemical studies (PAS-Alcian blue at pH 2.5) were performed to identify mucin in selected cases, and, in one instance, the neoplasm was studied by electron micros¬ were
The frequency
with which a pri¬ mary squamous cell carcinoma occurs in the parotid gland is not easy to ascertain by reviewing reports in the literature. Data are presented that indicate the incidence ranges from 0% to 3.4% of all parotid tumors.1 Piqued by this diversity and also because we have been impressed by the apparently low incidence of this -
Accepted
for publication Feb 2, 1976. From the departments of pathology (Drs Batsakis, McClatchey, and Regazi) and otorhinolaryngology (Dr Johns), University of Michigan Medical School, Ann Arbor, Mich. Reprint requests to Department of Pathology, University of Michigan Medical School, 1335 E Catherine St, Ann Arbor, MI 48104 (Dr Batsa-
kis).
copy.
After review,
only
two
neoplasms qual¬
ified as primary squamous carcinomas of the parotid gland. Five of the so-called primary squamous cell carcinomas were mucoepidermoid carcinomas, and seven were metastatic carcinomas that origi¬ nated in the oral cavity, oropharynx, or skin of the lateral part of the face. The case histories of the two patients with primary squamous cell carcinomas are briefly described.
REPORT OF CASES Clinical Findings
61-year-old man who had a at the angle of the right mandible of three years' duration was seen at the University of Michigan Hospital. A tender, painful, hard, and fixed Case 1.—A
painful
mass
6.0 x 4.0
x
3.0-cm
mass was
found in the
superficial lobe of the right parotid gland. There were no palpable lymph nodes. Results of oral, nasopharyngeal, and indi¬
laryngoscopic examinations were neg¬ ative. Although the mass was fixed to the overlying skin, there were no demonstrable lesions of the skin of the head and neck. Chest roentgenograms gave negative find¬ ings. The patient underwent a total paroti¬ dectomy with an interposition graft of the greater auricular nerve and a radical dissection of the right side of the neck. Two lymph nodes from the supraomohyoid portion of the neck dissection contained metastatic squamous cell carcinoma. At the time of a 21-year follow-up, the patient had no evidence of recurrence or métastases. rect
Case 2.—A 74-year-old woman entered the University of Michigan Hospital com¬ plaining of a swelling at the angle of the left mandible that had been present for the preceding six weeks. A 3.0 3.0 x 3.0-cm, firm, fixed, nontender mass was demon¬ strated in the superficial lobe of the parotid gland. There was a slight weakness of the orbicularis oris muscle. The left jugulodigastric lymph node was hard, yet
Downloaded From: http://archotol.jamanetwork.com/ by a Georgetown University Medical Center User on 05/22/2015
movable. Complete examination of the upper aerodigestive tract did not reveal a neoplasm. Chest x-ray films were normal. The patient underwent a total parotidec¬
tomy and sacrifice of the facial nerve (except for the frontal branch). The
seventh nerve was grafted with a section from the great auricular nerve. A radical dissection of the left side of the neck, including the sternocleidomastoid muscle was also performed. Only one (jugulodi¬ gastric) lymph node of 20 removed contained metastatic, well-differentiated squamous cell carcinoma.
Pathologic Findings The gross and microscopical appearance of both neoplasms were nearly identical. Both neoplasms were grayish-white, with variable degrees of cavitation, most severe in case 1. The superficial lobe was completely replaced in the neoplasm from the patient in case 1. Two thirds of the superficial lobe was replaced by the
neoplasm in case 2. Histologically, both neoplasms were moderately well differentiated, keratinizing squamous cell carcinomas (Fig 1). Both infiltrated the adjacent salivary gland parenchyma peripherally from a central cystic area. Although the latter could be interpreted as a dilated neoplastic duct, this would be entirely speculative and there was no direct proof. In neither gland was there microscopical evidence of un¬ derlying sialadenitis or ductal squamous metaplasia. Electron microscopy was performed on the buffered, formalin-fixed neoplasm from case 2, and this is shown in Fig 2.
Fig 1 .—Infiltrating margin of keratinizing squamous cell carcinoma in case 1. Histopath¬ ological appearance of primary squamous cell carcinoma in case 2 was nearly identical (hematoxylin-eosin 400).
COMMENT
Our study indicates that primary squamous cell carcinoma of the parot¬ id gland is a rare neoplasm at the
University of Michigan Hospital. The incidence of 0.3% of all parotid tumors during a 25-year period compares nearly exactly with that reported by Eneroth' after
review of 2,158 earlier publica¬ parotid tion, Eneroth' cited an incidence of 0.1% and included primary squamous cell carcinoma of the parotid in a "miscellaneous" category along with primary melanoma and malignant supporting tissue neoplasms of that gland. Woods et al,"' after studying 1,360 primary tumors of the parotid gland, gave an incidence of 1.5% for primary squamous cell carcinomas. These neoplasms made up nearly 10% a
tumors. In
an
Fig 2.—Electron microscopic appearance of squamous cell carcinoma in case 2. Epithelial cells contain abundant tonofilaments that are in bundles in some cells. Cells are connected by well-developed desmosomes (original magnification 7,500).
Downloaded From: http://archotol.jamanetwork.com/ by a Georgetown University Medical Center User on 05/22/2015
of their primary malignant tumors of the parotid gland. In the study of Spiro et al,6 there were ten cases of primary squamous cell carcinoma of the parotid gland in a total of 1,875 parotid tumors (0.5%). These made up 3% of all primary malignant neo¬ plasms of the parotid gland. The foregoing statistics contrast with the 3.4% incidence given by Foote and Frazell- in 1953 (Table) and very likely reflect a refinement in histopathologic diagnosis and classifi¬ cation since their paper. Before ascribing a primary origin of a squa¬ mous cell carcinoma in the parotid gland, one must exclude mucoepidermoid carcinoma and extension or metastasis to the parotid gland from an extraparotid source. Foote and Frazell- were cognizant of this, often requiring accessory data before deem¬ ing the lesion as primary in the sali¬ vary gland. With regard to mucoepidermoid carcinomas, this quotation from their paper is pertinent: "We have on a number of occasions clas¬ sified certain salivary gland tumors as squamous and then later changed this classification to mucoepidermoid af¬ ter more material from the primary,
Cell Carcinomas of the Parotid Gland
Primary Squamous
No. of Pri-
Series
University of Michigan
Eneroth« EnerotW Woods et ais Spiro et al« Foote and Frazell*
No. of Parotid Tumors 580 802
2,158
mary
Squa-
Cell Carcinomas mous
(0.3%) (0.1%) 7(0.3%) (1.5%) 2 1
1,360 1,875
10(0.5%)
766
26(3.4%)
or metastatic tumors be¬ available for study."- Such was the situation in five of our cases, where additional tissue and/or mucin stains appropriately classified the lesion in question.
recurrent, came
If, additionally, métastases or con¬ tiguous involvement are excluded, the frequency of primary squamous cell carcinoma is probably nearer to 1% or less of all parotid gland tumors.7 This figure is very near the 1.5% incidence given for métastases to the parotid gland from squamous cell skin cancer of the head and neck.s The anatomic site of origin for primary squamous cell carcinomas of
the parotid gland has not been traced, but as Foote and FrazelP have pointed out, it is only rational to ascribe them to duct origin. As in our two cases, the local infiltration by the neoplasm ob¬ literates an identifiable point of
origin.
To our knowledge, all, or nearly all, of the reported primary squamous cell carcinomas of the parotid gland have been well or moderately well differen¬ tiated carcinomas.-" There is no mucus production, and intracellular keratinization, intercellular bridging, and keratin pearl formation are often noted. In short, there is nothing to histologically distinguish these squa¬ mous cell carcinomas from those arising in other sites. Local recurrence and regional lymph node métastases are the usual outcome for patients with primary squamous cell carcinomas of the pa¬ rotid gland.2 Spiro et al" report that seven of their ten patients eventually manifested lymph node métastases. Ultimate survival appears to depend more on the clinical stage of the disease than on the histologie ap¬ pearance of the tumor. Distant metastases are not a prominent feature. "
References 1. Bruzelius S, Cederquist E, Tinell F, et al: Tumors of the parotid gland: A histologic study and results of combined surgical and radiological treatment. Acta Chir Scand 114:1-9, 1957. 2. Foote FW Jr, Frazell EL: Tumors of the major salivary glands. Cancer 6:1065-1133, 1953. 3. Eneroth C-M: Salivary gland tumors in the parotid gland, submandibular gland, and the palate region. Cancer 27:1415-1418, 1971.
4. Eneroth C-M: Histopathological and clinical aspects of parotid tumours. Acta Otolaryngol Suppl 191:1-99, 1964. 5. Woods
ence
JE, Chong GC, Beahrs OH: Experiprimary parotid tumors. Am J
with 1,360
Surg 130:460-462, 1975. 6. Spiro RH, Huvos AG, Strong EW: Cancer of the parotid gland: A clinicopathologic study of 288 primary cases. Am J Surg 130:452-459,
1975. 7. Batsakis JG: Tumors of the Head and Neck: Clinical and Pathological Considerations. Baltimore, Williams & Wilkins Co, 1974, p 25. 8. Ridenhour CE, Spratt JS Jr: Epidermoid carcinoma of the skin involving the parotid gland. Am J Surg 112:504-507, 1966.
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