Key-words:
Neck node dissection - palliative radiotherapy - primary cutaneous apocrine carcinoma
- wide local excision
Introduction
Primary cutaneous apocrine carcinoma (PCAC) is a rare cutaneous malignancy with an
incidence of 0.005–0.017/100,000 patients per year.[[1]] While around 200 cases have been reported in the literature, commonly noted in
areas such as the axilla, there have only been a few cases originating from the scalp.[[2]],[[3]]
Demographically, these malignancies have a Caucasian predominance with an equal distribution
in both sexes. They commonly show a peak around the 6th and 7th decades of age, with
a median age of 67 years, which was noted in the largest cohort studied to date.[[1]]
Its presentation varies, where in it can occur as both uninodular and multinodular
growths with varying colors.[[1]],[[2]] Reports have shown an infiltration of overlying epidermis. Clinically, these masses
are indurated, painless, and may be associated with benign lesions such as nevus sebaceous.[[4]]
As these lesions are vague in presentation and appearance, a good clinical evaluation
and suspicion is required, as they are difficult to differentiate from metastatic
skin lesions, especially from metastases of breast adenocarcinoma.[[1]]
Among the past series of over 200 cases of PCAC, only few have a detailed description
of scalp primaries.[[1]] While some cases have been reported to show longer durations with periods of rapid
growth, it is observed that most of these lesions typically are eminent within a year
before diagnosis.[[5]],[[6]]
Case Report
A 66-year-old male, a known case of coronary artery disease and hypertension, presented
with a firm, nontender swelling over the parieto-occipital area of the scalp. It originated
as a small swelling which increased in size over a period of 6 months [[Figure 1]]. He had no complaints of any headache or any neurological deficits.
His CT brain showed no calvarial involvement [[Figure 2]].
Figure 1: Gross appearance of the scalp lesion measuring 5 cm × 4 cm × 3 cm
Figure 2: No intracranial extensions
A wide local excision of the parieto-occipital lesion was done in the prone position
under general anesthesia. A vertical elliptical incision was made around the lesion.
The lesion was removed en masse along with underlying periosteum [[Figure 3]]a, [[Figure 3]]b, [[Figure 3]]c.
Figure 3: (a) No intracranial extensions. (b) Gross section of the lesion showing the overlying
skin and undersurface of the tumor. (c) Gross section of the lesion showing the overlying
skin and undersurface of the tumor
Plastic surgery assistance intraoperatively was taken to create a large rotation advancement
flap over the defect along with the placement of a split skin graft, harvested from
the thigh [[Figure 4]] and [[Figure 5]].
Figure 4: Advancement rotation flap of the skin defect with split skin graft
Figure 5: Postoperative wound showing good healing
Grossly, the pathology report was suggestive of a lesion with subcutaneous tissue
measuring 11 cm × 7.5 cm × 4.5 cm. The skin surface showed a nodularity of around
2.5 cm diameter with an underlying tumor measuring 5 cm × 4 cm × 3 cm abutting the
deep margin focally. The cut section was gray tan in color with areas of focal myxoid
and hemorrhage.
Microscopically, the sections showed skin with underlying dermis and subcutis showing
an unencapsulated lesion with jagged and pushing borders [[Figure 6]]. It was primarily composed of tubules with fusion, which were cribriforming. Some
cells showed cystic dilation, intraforaminal foamy histiocytes with solid and papillary
pattern of arrangement. These cells were lined with moderate to abundant eosinophilic
granular to partly vacuolated cytoplasm. Patchy hemorrhagic, infarcted areas with
foamy histiocytes were noted with no ulceration of overlying skin [[Figure 7]].
Figure 6: Underlying dermis and subcutis showing an unencapsulated SOL with jagged and pushing
borders
Figure 7: Presence of foamy histiocytes with papillary arrangement
A high-resolution computed tomography (CT) of the chest showed no neck lymph nodes.
A positron emission tomography CT done showed no evidence of any primaries or metabolically
active lesions elsewhere in the body. He was advised a strict follow-up and explained
the need for adjuvant radiotherapy.
Discussion
A literature review conducted via the PubMed engine in 2019 for patients with PCAC
revealed 19 cases with detailed reports regarding the clinical presentation, treatment
methods, and prognosis of the disease.[[1]] The study cohort included 11 (57.9%) females and 8 (42.1%) males with a mean age
of 57 years. The average size was variable with an average of 3.1 cm. 12/19 (63.2%)
patients were presented with the only local cutaneous disease. 3/19 (15.8%) patients
were presented with cervical lymphadenopathy at the time of diagnosis.
While metastatic disease was not present at the time of diagnosis in any of the reported
cases, the average size of the metastatic lesions was higher than the average size
of nonmetastatic lesions. Common sites of distant metastasis occurred in the distant
lymph nodes, the bones, the brain, and the lungs.
Surgical excision (local complete vs. wide or radical) was the primary treatment done
in 18/19 (94.7%) patients in that study.
Local recurrences without positive regional lymph nodes, primary treatment was wide
excision of the tumor. Neck dissection, radiation, or both were the treatment in cases
of positive regional lymph node metastasis. Those with metastatic disease, palliative
chemotherapy and/or radiotherapy was the treatment done.
From the time of metastatic diagnosis, survival ranged from approximately 1–4 years,
with an average of 2.25 years.[[1]],[[2]],[[3]],[[7]],[[8]],[[9]]
The data suggested that the size of the primary at initial presentation was directly
proportional to a poor prognosis, with a higher tendency to metastasize; prognosis
is often fatal upon the evidence of metastatic disease.[[1]]
Our case had no distant metastasis at presentation. As histopathology revealed negative
wide margins on all sites, except a 1 mm margin on the deeper aspect, adjuvant radiotherapy
was advised.
The current consensus suggests the use of wide surgical resection; however, due to
insufficient data, surgical margins have not been standardized so far and 1–2 cm may
provide sufficient eradication of tumor cells. Lesions exceeding 5 cm, the use of
adjuvant radiation in the treatment protocol is said to improve survival rates.[[10]],[[11]]
In node-negative cases, there is no need for a neck dissection. Neck dissection followed
by adjuvant radiotherapy was offered to the patient presented with cervical lymph
node metastasis.
Sentinel lymph node biopsy (SLNB) was suggested by Hallowell,[[1]] but due to the low incidence rate of PCAC, SLNB has not undergone prospective evaluation.
Due to the low incidence of PCAC, individualized treatment should be addressed. Chemotherapy
should be reserved for treating the advanced disease that often proves to be fatal
and the initiation of palliative care in these circumstances is inevitable.[[3]]
Our patient remains disease free after 2 months of surgery, consistent with literature.
Conclusion
Following an in-depth assessment of the literature on PCAC, it can be concluded that
the recommendation for surgical removal with cleared margins seems to be appropriate
among patients with local, node-negative disease. Good surgical clearance with wide
margins of 1–2 centimeters is considered the accepted standard. However, there has
been no evidence available currently, to show the benefit of adjuvant treatment for
PCAC. The use of chemotherapy and radiotherapy may also be considered in patients
with advanced and distant disease, as well as chronic recurrence, but should be decided
on a case-to-case basis.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms.
In the form the patient(s) has/have given his/her/their consent for his/her/their
images and other clinical information to be reported in the journal. The patients
understand that their names and initials will not be published and due efforts will
be made to conceal their identity, but anonymity cannot be guaranteed.
